To deliver tailored pain science education, assessing children’s biopsychosocial pain concepts is necessary. As validated tools are lacking, a new tool is presented, the biopsychosocial pain concept matrix (BiPS matrix), which assesses children’s biological, psychological, and social pain concepts in five domains according to the Common-Sense Model of Self-Regulation (Hagger and Orbell, 2003): (1) illness identity, (2) causes, (3) consequences, (4) duration, and (5) treatment. The present preliminary study aims to (1) assess the items’ readability and understandability in cognitive interviews with N = 9 healthy children (9 to 19 years, M = 13.78 years, SD = 3.05; 44% female) and (2) pre-test the BiPS matrix within an online survey of N = 27 healthy children (9 to 19 years, M = 13.76 years, SD = 3.03; 56% female). Results revealed difficulties in understanding some items. Children’s understanding increased with age. Age, chronic pain status, and pain in the social environment were positively associated with the BiPS total score, whereas the latter explained the most variance in pain concepts of children. Patient-focused methods such as cognitive interviews proved essential in testing the readability and understanding of items in children. Future studies are warranted to further validate the BiPS matrix.