Sexual behavior is influenced by social and communication deficits in autism spectrum disorder (ASD) and is a serious challenge for parents who lack effective strategies for providing sexual education to their children with ASD. The purpose of this study was to explore Iranian parents’ experiences of psychological distress in dealing with the sexual behaviors of their children with ASD. This qualitative study was designed following the conventional content analysis approach. Semi-structured and in-depth interviews were conducted with 27 parents of children with ASD aged 8–34 years. All interviews were audio-recorded and transcribed verbatim. The data were collected through purposeful sampling and continued until data saturation. The worries theme was extracted from data interpretation using qualitative content analysis, and this theme entailed four subthemes: 1) sexual vulnerability, 2) unintended social consequences, 3) psychological suffering, and 4) confusion about the future of a child’s sex life. This study emphasized the importance of paying attention to parents’ concerns about the sexual behaviors of children with ASD. Parents’ psychological distress is a major obstacle to proper coping with sexual behaviors, and using coping strategies may help reduce psychological distress in parents of children with ASD. Therefore, it is necessary to design, implement, and evaluate culture-appropriate educational programs to address parents’ concerns regarding the sexual health of a child with autism.