To meet children's needs for information and support when a parent has a mental illness, Beardslee's family intervention was implemented in Swedish psychosis care. The present study aimed to gain understanding of how parents' with psychosis and their children experienced having taken part in Beardslee's family intervention. The study followed COREQ guidelines. Semi-structured interviews were conducted with 15 participants (8 parents with psychosis and 7 children) who had participated in the family intervention. Data were analysed with content analysis. Results showed that the parents perceived that the intervention had contributed to improved illness knowledge, communication, and understanding in the family. They also appreciated receiving support in finding an age-adapted way of explaining their illness, but asked for structured follow-ups in order to maintain communication. However, comparing parents' and children's interviews led to discrepancies in perceptions of the overall benefits of the intervention. In conclusion, parents with psychosis need continual support in talking to their children about their illness. Furthermore, discrepancies between parents' and children's interviews show the importance of multi-perspective data collection when studying intervention effects.