Whether parental psychiatric disorders are associated with autism spectrum disorder (ASD) in offspring has remained inconclusive. We examined the associations of parental psychiatric disorders with ASD in offspring. This population‐based case–control study used Taiwan's National Health Insurance Research Database to identify a cohort of children born from 2004 to 2017 and their parents. A total of 24,279 children with ASD (diagnostic ICD‐9‐CM code: 299.x or ICD‐10 code F84.x) and 97,715 matched controls were included. Parental psychiatric disorders, including depressive disorders, bipolar spectrum disorders, anxiety disorders, obsessive–compulsive disorder, schizophrenia, substance use disorders, autism spectrum disorder, attention‐deficit hyperactivity disorder (ADHD), and adjustment disorders were identified. Conditional logistic regressions with covariate adjustment were performed. The results suggest that parental diagnosis with any of the psychiatric disorders is associated with ASD in offspring (adjusted odds ratio AOR = 1.45, 95%CI: 1.40–1.51 for mothers; and AOR = 1.12, 95%CI: 1.08–1.17 for fathers). ASD in offspring was associated with schizophrenia, depressive disorders, obsessive–compulsive disorder, adjustment disorders, ADHD and ASD in both parents. The relationship between parental psychiatric disorders and the timing of the child's birth and ASD diagnosis varied across the different psychiatric disorders. The present study provides supportive evidence that parental psychiatric disorders are associated with autistic children. Furthermore, because the associations between parental psychiatric disorders and the timing of child's birth and ASD diagnosis varied across psychiatric disorders, the observed relationships may be affected by both genetic and environmental factors. Future studies are needed to disentangle the potential influence of genetic and environmental factors on the observed associations. Lay Summary Parents of autistic children are more likely to have psychiatric disorders. This might partially be due to shared genetic factors between autism and other psychiatric disorders. In addition, rearing autistic children might be stressful, leading to increased possibility of psychiatric disorders among parents. We used Taiwan's National Health Insurance claims database to identify 24,279 autistic children and 4‐fold number of comparison children. The prevalence of psychiatric disorders among their parents were assessed. Specifically, we explored the temporal relationship between the timing of the diagnosis of parental psychiatric disorders and children's birth and autism diagnosis. We found parents of autistic children had higher risk of psychiatric disorders, especially for schizophrenia, depressive disorders, and adjustment disorders. Notably, we found that the risk of adjustment disorder was elevated after the child's birth. This finding indicates that the risk of parental psychiatric disorders may be attributable to not only genetic risk but also environmental factors, which are potentially modifiable. Further studies are needed to disentangle the influence of genetic and environmental factors and to determine effective intervention to reduce the risk of parental psychiatric disorders.