This manuscript is an accompanying resource of the original research article entitled “Child development at 6 years after maternal cancer diagnosis and treatment during pregnancy” and present data that compare the outcome of 6-year-old-children born to women diagnosed with cancer during pregnancy (with or without treatment during pregnancy) (study group) with children born after an uncomplicated pregnancy (control group). Oncological, obstetrical and neonatal data were collected. Neurodevelopment was examined by clinical evaluation and neuropsychological testing (including intelligence, attention and memory tests) and by general health and behavior questionnaires. Cardiac evaluation included electro- and echocardiography. Univariate analyses of covariance were used to investigate between-group differences. A subgroup analysis was performed in chemotherapy-exposed children versus controls and anthracycline-exposed versus controls. Additionally, the incidence of behaviour problems was compared to matched controls for children whose mothers died and for those with surviving mothers.