Background Children diagnosed with cancer are at increased risk for the development of psychosocial problems. Currently, no qualitative and quantitative tests are available to measure their need for psychosocial follow-up care. The NPO-11 screening was developed to tackle this issue. Patients and Methods 11 dichotomous items were generated to measure self- and parent-reported fear of progression, sadness, avolition, self-esteem problems, school and vocational problems, somatic complaints, emotional withdrawal, social disintegration, pseudo-maturity, parent-child conflicts, and parental conflicts. Data from N=101 parent-child dyads were obtained to validate the NPO-11. Results Self- and parent-reported items showed few missing values and response frequencies without floor or ceiling effects. Inter-rater reliability was fair to moderate. Factor analysis confirmed a single-factor model and therefore an overall NPO-11 sum score. Self- and parent-reported sum scores had sufficient to good reliability and large correlations with health-related quality of life. Conclusion The NPO-11 is a screening for psychosocial needs in pediatric follow-up care with good psychometric properties. It may help to plan diagnostics and interventions for patients transitioning from in-patient to out-patient treatment.