Locations and Physicians

Guillermo Gonzalez-Osete, MD

Patient Portal


Medical Oncology & Hematology


Tucson - St. Mary’s Medical Oncology
1620 W. St. Mary’s Road
Tucson, AZ 85745
Phone: (520) 624-7445
Fax: (520) 623-6145

Nogales - Mariposa Community Health Center Medical Oncology
1710 N. Mastick Way
Nogales, AZ 85621
Phone: (520) 624-7445
Fax: (520) 623-6145

Nogales - Western Avenue Medical Oncology
507 W. Western Avenue
Nogales, AZ 85621
Phone: 520-624-7445
Fax: 520-623-6145

Guillermo Gonzalez-Osete, MD


Nogales Federal Preparatory School

Medical School

Universidad Autonoma of Guadalajara, Inc.


Hermosillo General Hospital


Hospital Espanol de Mexico


Medical Oncology and Hematology, University of Arizona Cancer Center

Board Certification

Medical Oncology and Internal Medicine


Dr. Gonzalez-Osete was trained at the Arizona Cancer Center in hematology and oncology. Upon completion of his fellowship, he worked as Clinical Assistant Professor of Medicine at the Arizona Cancer Center for four years. During that time he was part of the bone marrow transplant team.

Dr. Gonzalez-Osete treats breast, lung, and other cancer types. He is board-certified in medical oncology and internal medicine. His practice is located at Arizona Oncology's St. Mary office in Tucson, as well as at two satellite clinics in Nogales: the Mariposa Community Health Center and the Santa Cruz Urology Clinic.

Dr. Gonzalez-Osete has been published multiple times and he has co-authored several book chapters. For a number of years he gave presentations at ¡VIDA! The Annual Mujer Latina Breast Cancer Conference. He currently serves as Hematology & Oncology Section Chairman for St. Mary's Carondelet Hospital and as Blood Transfusion Committee Chairman at St. Mary's Hospital.