Although sex differences have been investigated in chronic pain populations, little is known about sex differences in the pain experience of paediatric oncology patients and also whether their parents rate the pain experience differently for boys and girls. The aim of the present study was to determine if (1) boys and girls with cancer differ in current perception and past recollection of cancer-related pain and (2) if adolescents' and parents' pain ratings differ in relation to the sex of the adolescent. One hundred twelve adolescents with malignant diagnoses (12 to 18 years) and their parents participated in the study. Girls reported higher pain intensity within the last 7 days and 4 weeks despite similar diagnosis, physical status, duration of diagnoses, and main pain causes. When asked for pain intensity that dated back in time, parent and adolescent ratings diverged, with a trend for parents to reporting higher pain intensity in boys and lower pain intensity in girls, particularly for pain in the preceding 7 days. The present study provides preliminary evidence for sex differences in the recalled pain experience of adolescents with malignant diagnoses. Although boys and girls experience present pain similarly and hence should be treated similarly, girls recall higher pain intensity than boys. Future studies should address whether negative memories in girls play a significant role and may have an impact on girls' well-being and pain-related distress. Additionally, psychosocial factors such as gender role expectations may need to be investigated. Parental variables and their impact on parents' pain ratings, especially for ratings of precedent pain, warrants further investigation. CONCLUSIONS Girls with malignant diagnoses differ from boys in their recalled pain intensity ratings, with girls reporting higher pain intensity. Additional pain management strategies referring to the memory of pain may need to be implemented.