Marianne Lennon, MD

Marianne Casilla-Lennon, MD is a board-certified general urologist and Assistant Professor of Urology at the Yale School of Medicine. She provides comprehensive care for both men and women, with clinical expertise in erectile dysfunction, kidney stones, urinary incontinence, overactive bladder, benign prostatic hyperplasia (BPH), prostatic diseases, and urinary tract obstruction. She is skilled in minimally invasive, open, and office-based urologic procedures.

Dr. Casilla-Lennon is dedicated to individualized, patient-centered care. “My goal is to ensure patients feel heard, informed, and empowered to take an active role in their care,” she says. She was drawn to medicine by a desire to make a meaningful impact in people’s lives, and found in urology a field that offers a wide range of therapeutic options, behavioral, medical, and surgical, tailored to each patient’s condition and goals.

In addition to her clinical practice, Dr. Casilla-Lennon plays a leading role in medical education at Yale. She serves as Director of Medical Education and Director of the Resident Medical Education Fellowship in the Department of Urology. In addition, she is the Urology Resident Director at the West Haven Veterans Affairs Medical Center. She oversees medical student curricula including the clerkship, sub-internship, pre-clinical didactics, and innovative electives such as a multidisciplinary surgical rotation and a basic surgical anatomy course. She also mentors medical students and residents through scholarly projects, professional development, and clinical education. Her work reflects a deep commitment to training the next generation of urologists through hands-on teaching, curricular innovation, and longitudinal mentorship.

Dr. Casilla-Lennon has also contributed to research on a range of topics, including health systems, medical education, and clinical urology.