We aimed to adapt the Modified Checklist for Autism in Toddlers to Turkish culture. The Modified Checklist for Autism in Toddlers was filled out independently by 191 parents while they were waiting for the well-child examination of their child. A high screen-positive rate was found. Because of this high false-positive rate, a second study was done in which the Modified Checklist for Autism in Toddlers was administered by health-care staff in a short interview with two groups of parents. The first group (the high-risk group) comprised 80 children aged 18-36 months, who were initially diagnosed with pervasive developmental disorders. The second group (the low-risk group) comprised 538 children of the same age, who were followed regularly by the well-child clinic. Two screen positives were found in the low-risk group. These two children, a random sample of 120 children from the low-risk group, and all the high-risk group were invited to a clinical evaluation. The diagnostic power of the Modified Checklist for Autism in Toddlers was assessed against clinical diagnosis and the Childhood Autism Rating Scale. The positive predictive value of the Modified Checklist for Autism in Toddlers was found to be 75%. Our findings led us to conclude that the Modified Checklist for Autism in Toddlers is a useful tool in Turkey for screening of pervasive developmental disorders in primary care, but in our culture, it is completed more accurately when health-care personnel ask the parents the questions. This study shows that Modified Checklist for Autism in Toddlers screening should be adapted based on culture and setting.