BACKGROUND: This study was aimed at assessing fathers' and mothers' distress 6 months after a pediatric cancer diagnosis and at determining whether this is related to the level of family psychosocial risk 1 month after the diagnosis. METHODS: A sample of 192 families completed the electronic Psychosocial Assessment Tool (ePAT) 1 month after the diagnosis. At 6 months after the diagnosis, 119 mothers and 98 fathers completed the Distress Thermometer for Parents (DT-P; of which n=132 had also completed the ePAT at baseline). The DT-P consists of a thermometer score ranging from 0 to 10 (with a score ≥ 4 indicating clinical distress), problem domains (total, practical, social, emotional, physical, cognitive, and parenting for children < 2 years old and for children ≥ 2 years old), and a desire for a referral. The DT-P scores of mothers and fathers were compared with the scores of a reference group of 671 mothers and 463 fathers with healthy children. Within the pediatric cancer group, the DT-P scores of families with elevated total ePAT-scores were compared with the DT-P scores of parents with universal ePAT scores. RESULTS: Parents of children with cancer more often reported clinical distress on the DT-P than parents of healthy children (fathers, 59.2% vs 32.3%; P <.001; mothers, 63% vs 42.3%; P <.001) and reported more problems on all DT-P domains (P <.001 to P =.042) except for the parenting domain for children < 2 years old. Furthermore, the ePAT predicted parental distress 6 months after the diagnosis because parents with elevated ePAT scores reported more problems than parents with universal scores on the DT-P thermometer and most of the DT-P domains (P <.001 to P = 1.00). CONCLUSIONS: Initial ePAT risk scores at diagnosis are predictive of future mean levels of parental distress. Cancer 2018;124:381-90.