Addressing perfectionism through psychological interventions represent an important avenue that can contribute to population’s psychological wellbeing. This study investigates the effect of an online intervention program for perfectionism implemented in Romania. After completing the online screening 41 adult volunteer participants with elevated levels of perfectionism were selected for this open trial. The Frost Multidimensional Perfectionism Scale (FMPS) Concern over Mistakes, and Personal Standards subscales, and Almost Perfect Scale–Revised (APS-R) Discrepancy and High standards subscales were selected as primary outcome measures. As part of the intervention program we used psychoeducation and cognitive-behavioral techniques to reduce perfectionism. Following this 45-days program participants displayed lower levels on both perfectionistic concerns and perfectionistic striving (i.e., all primary outcome measures yielding a within-group Cohen’s d effect size between .23 and .55) and lower levels of depression, anxiety, stress, obsessive-compulsive symptoms, as well as increased self-acceptance (i.e., within-group Cohen’s d effect size between .11 and .40). Despite inherent limitations, these results provide initial evidence for the effectiveness of online interventions addressing perfectionism in a new culture. Using shorter, more engaging versions for guided online perfectionism interventions is proposed as a possible avenue to be tested in the future.