Prior study shows that many Bangladeshis have mental health concerns. A certain percentage have obsessive-compulsive disorder (OCD). Impulse buying accounts for 40% of all purchases. Therefore, studying how OCD affects afflicted consumers’ purchasing behavior would be intriguing. In this study among 203 respondents, 11 had severe OCD and 121 had mild OCD. Impulse purchase behavior was studied using nine factors. An exploratory factor analysis with varimax rotation was performed on an eighteen-item questionnaire that measured OCD and impulsive purchase across nine variables. The Kaiser–Meyer–Olkin measure was used to assess sample size and variable correlations. Only eigenvalues greater than 1 were evaluated. One-sample T-test was also performed to examine the statistical significance of the difference between the general mean and the OCD-affected sample groups. OCD affects all nine impulse purchasing components, as shown by strong and moderate correlation values and significant t-values. Regression analysis showed that customer’s OCD level strongly influences instant purchase tendency among all the nine components.