AimThe present study aims to test whether different instructions, when using draw-and-write data collection techniques, can be especially suited for understanding specific aspects of children’s conceptions about health and illness.MethodThis is a mixed-method study and participants were 209 schoolchildren, aged 10 to 12 years, who were asked to draw-and-write following one of two different instructions (A or B) that were related to the concepts of health and illness. Texts were examined through content analysis based on a previously validated coding system (inter-rater agreement of 93%).ResultsFindings suggest that the instruction “what does it mean to you to be sick and what does it mean to you to be healthy?” allows a more direct access to experiences and feelings, and that the instruction “draw and write about what a sick person is and what a healthy person is” is more adequate to elicit children’s knowledge and perceptions.ConclusionThe study suggests that to elicit children’s concepts of health and illness, relevant for health education and health promotion interventions, the draw-and-write instructions should be phrased in impersonal general terms. In contrast, for clinical interventions, the instruction should be targeted to the child’s direct experience of being ill.