Due to co-morbidities and treatment resistant nature of pervasive developmental disorder (PDD), diverse combinations of regimens have been tried. This retrospective study aimed to explore adjunctive use of aripiprazole in children with PDD. Changes in illness severity were measured by Clinical Global Impression of Severity (CGI-S) and Clinical Global Impression of Improvement (CGI-I) in 14 aripiprazole-treated patients with PDD. Improvement of illness severity was observed after aripiprazole add-on (5.8±0.8 to 4.9±1.0, Z=-2.75, p=0.001). Mean dosage was 7.7 mg/day [standard deviation (SD) 3.3, range 5-15]. A higher mean dosage was observed in group with improvement in symptoms (t=-2.33, df =12, p=0.004). The target symptoms most effectively improved after using aripiprazole were positive psychotic symptoms (mean CGI-I: 2.0±1.4, 3 responders/4 patients, 75% response) followed by aggressive behavior (2.5±1.7, 3/4, 75%), self-injurious behavior (2.0±1.0, 2/3, 67%), stereotypic behavior (2.7±1.2, 2/3, 67%), tic (2.8±1.0, 2/4, 50%), irritability (3.5±2.1, 1/2, 50%), obsessive behavior (2.5±2.1, 1/3, 33%), hyperactivity (3.4±1.6, 3/7, 43%) and mood fluctuation (3, 0/1, no response). Five patients (35%) discontinued aripiprazole due to treatment-emergent adverse effects (akathisia, insomnia, withdrawal). The results of this study suggest that aripiprazole augmentation may be used safely in maladaptive behaviors of some populations of PDD. However, future studies are required to confirm these preliminary findings.