Meet Dr. Dianne McKenzie

I believe God calls us to a mission bigger than ourselves-to love fiercely, serve humbly, and change lives one heart at a time. For me, that mission is caring for kids, and I'm fired up to bring that calling to Cook Children's in Ennis, Texas, as I start a new chapter in 2025. My why is simple: every child deserves a champion who fights for their health, their joy, and their future. I'm here to be that champion, to make a difference in Ennis families, and to live out the truth that "the world may be different because I was important in the life of a child," as Forest Whitcraft said.

My journey began in San Antonio, where faith and grit shaped me. I earned my bachelor of arts in biology with a chemistry minor at Texas A&M University. I honed my skills in the master's program in biomedical sciences at Boston University School of Medicine, then answered God's call to return home for medical school at The University of Texas Health Science Center at San Antonio, earning my M.D. in 1999. My pediatric residency there was the foundation for a lifelong commitment to kids. For over 23 years, I've been a pediatrician in Amarillo, where I have volunteered with Hope Choice since 2002 to mentor pregnant mothers who find themselves in an unexpected or unplanned pregnancy. I have also served as chief of pediatrics at Northwest Texas Hospital and on the March of Dimes board. Now, I'm bringing that passion to Cook Children's in Ennis.

At Cook Children's, I'm ready to give Ennis families my best-every visit, every day. Whether it's a well-child checkup, sick visit, treating allergies, infections, or developmental needs, I'm here to listen, heal, and inspire. As a board-certified pediatrician, I'm equipped to guide kids from their first breath to their graduation, partnering with parents to build healthy, thriving futures. My practice at Cook Children's offers comprehensive care, from immunizations to counseling, with the same heart I've brought to every patient for over two decades. I'm thrilled to join a team known for excellence, serving alongside folks who share my fire for kids' health. And I'll be active in the community-ready to volunteer, mentor and show up for the children in Ennis.

I'm a wife to David McKenzie and a mom to four incredible blessings-Elizabeth, Landry, Sarah, and Joshua-who keep me grounded and remind me why I do this. Whether I'm hiking, cooking, or traveling with my family, I'm recharging to give more to the kids and families I serve. I'm not perfect, but I'm committed-heart and soul-to making a difference. Ennis, I'm here for your kids, your hopes, and your future. Come join me at Cook Children's, and let's make every moment count for your family.

Services

  • Acute illnesses
  • ADHD management
  • Chronic condition management
  • Developmental problems
  • Disease prevention
  • Flu shots
  • Hearing screens
  • Injury treatment
  • Obesity and weight management
  • Vision screens
  • Patient and parent education
  • School and sports physicals
  • Vaccines and immunizations
  • Well checks

Reviews

Average rating:

4.6
Questions were addressed
4.6
4.6 (31)
Provider explained things clearly
4.6
4.6 (31)
Likelihood of recommending this provider
4.6
4.6 (31)
Trust/confidence in physicians
4.5
4.5 (30)

What our families say

  • March 21, 2026

    Dr. McKenzie and [...] and the entire staff. They are always polite, they listen to my concerns and provide the best treatment for my daughter.

  • March 11, 2026

    This was a very good experience. I feel informed for what is going on and what to expect next visit.

  • March 03, 2026

    Everyone was very kind and concerned for my daughter's wellbeing. Very pleased with the entire team!

  • March 03, 2026

    Greeted with a smile, interactive conversation, excellent customer service, provided water when requested, acknowledged our concerns in a caring manner, great visit

  • March 02, 2026

    Everyone was so nice in the office and makes me happy to have made the switch.

  • March 02, 2026

    Dr. McKenzie was great! She is very sweet and told me what could be done and then told me what she suggested and then let me pick what I wanted to do for my child. I have never had a better experience with a pediatrician and wish I would've found her sooner.

  • February 20, 2026

    Our baby gave us a scare and Dr McKenzie and her staff helped us overcome our issue

  • February 20, 2026

    Dr McKenzie and her entire staff are all wonderful, they show so much compassion for the patients they see

  • February 20, 2026

    The entire staff was very friendly and helpful!

  • February 20, 2026

    Thank you for thr ease in transition from the pre existing pratice to the current providers

  • January 12, 2026

    Everyone was great

  • January 12, 2026

    Everything was great and quick

  • January 08, 2026

    McKenzie is very good at what she does. She's very informative and does the extra mile to explain everything precise and clear. She even researches to confirm certain topics. Highly recommend!

  • December 31, 2025

    Staff very patient.

  • December 31, 2025

    Doctor was very informative and personable.

  • December 23, 2025

    Dr McKenzie was great in every way! -Patience, understanding, explanations, interactions. My son and I both had a wonderful experience with her.

  • October 29, 2025

    The new doctor is very nice I enjoyed speaking with her !

Gallery

A pediatric physician examining a child at a primary care office in Ennis, Texas
A pediatric physician at a primary care office in Ennis, Texas, near the Dallas-Fort Worth metroplex
A primary care physician hugging a child at a pediatric office in Ennis, Texas

Education

  • Medical school:
  • UTHSCSA, San Antonio, TX
  • Residency:
  • UTHSCSA, San Antonio, TX
  • Board certifications:
  • American Board of Pediatrics

Affiliations

  • Cook Children's Physician Network

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