We investigated pharmacotherapy trends for obsessive-compulsive disorder (OCD) patients at a Korean tertiary hospital from 2008 to 2017. Out of 1894 patients, 82.9% received at least one psychotropic medication, with prescription rates increasing over time. The most frequently prescribed drug classes were selective serotonin reuptake inhibitors (SSRIs, 80.5%), anxiolytics (57.5%), antipsychotics (47.2%), other antidepressants (21.1%), and mood stabilizers (18.4%). Combination therapy was administered to 79.7% of medicated patients, with SSRIs, anxiolytics, and antipsychotics being the most common combination. Comorbidities significantly increased the prescription rates of all psychotropic classes (P < 0.001). Our study offers insights that may aid in bridging the gap between OCD treatment guidelines and real-world clinical practice.