Background: Under Ohio Medical Marijuana Control Program rules, Ohio physicians that recommend medical marijuana (MMJ) to patients must possess a Certificate to Recommend (CTR) from the State Medical Board. Although a pre-program state survey indicated that more than a quarter of Ohio physicians were likely to recommend MMJ, only 473 physicians obtained CTRs in the first year of the program, amounting to just 1.39% of the physician workforce. The purpose of this study is to evaluate demographic factors that influence a physician's decision to obtain the CTR. Method: Using physician demographic data extracted from Ohio's databases of medical licensees and CTR holders, as well as the American Medical Association Physician Masterfile, prevalence ratios for CTR holders were calculated for specialty, medical degree (Doctor of Medicine, MD, vs. Doctor of Osteopathy, DO), age and gender. A multivariate model was implemented to generate adjusted prevalence ratios (aPRs) reflecting the independent effects of specialty, degree, and age. To assess temporal variations in CTR acquisition, per-specialty CTR counts were also plotted as a function of program month. Results:The best-represented specialties among CTR holders were Family Medicine (29.11%), Internal Medicine and its subspecialties (22.57%), and Anesthesiology (9.07%). Expressed as an adjusted per-specialty prevalence ratio in reference to Family Medicine, the dominant specialty was Physical Medicine and Rehabilitation (aPR 2.08, 95% CI 1.34-3.24), with the lowest measurable prevalence ratios found in Pediatrics (aPR 0.17, 95% CI 0.10-0.30) and Surgery (aPR 0.33, 95% CI 0.22-0.50). DOs were more likely to obtain CTRs than MDs (aPR 1.72, 95% CI 1.39-2.15). The mean age of CTR holders was 54.03 +/− 11.43, vs. 51.13 +/− 13.38 for non-CTR holders (p < .0001). Although gender could not be included in the multivariate model, males were more likely than females to obtain a CTR (PR 1.54, 95%CI 1.26-1.89). A plot of per-month CTR acquisition by specialty demonstrated a fairly consistent specialty distribution of CTRs in the first year, as well as variations in overall CTR acquisition that may correspond to programoperational events.Conclusion: Specialty, type of medical degree, and age all correlate independently with the likelihood of registering to recommend medical marijuana in Ohio. Specialty distribution of CTRs remained fairly consistent in the program's first year, although overall CTR acquisition may be sensitive to program-operational events such as delays in dispensary opening or product availability.