Scientific research into the reduction of stigmatization, particularly related to specific problems such as Obsessive-Compulsive Disorder (OCD), is scarce. In the present study, we examine the impact of a video-based anti-stigma intervention program for OCD in a pretest-posttest control group research. After being randomly assigned to either an intervention (n = 101) or control group (n = 96), the participants reported their attitudes on a hypothetical case vignette before and after OCD vs. Multiple Sclerosis (MS) videos, and again six months later as a follow up assessment. The mixed design analyses for the group comparisons indicated that although there was no significant difference in the measures of the control group, the participants watching the anti-stigma OCD video, in which the focus was psychoeducation and interaction strategies, reported significantly lower scores on social distances and negative beliefs for the case vignettes they read, and this difference was maintained six months later. Then, the present results indicate the effectiveness of our anti-stigma intervention program for OCD. Interventions to reduce stigmatization can also be viewed as effective tools for changing the attitudes of people toward OCD, although further research and applications are needed related to specific disorders if a long-lasting impact is to be achieved.