The cultural background of patients and parents is increasingly recognized as a relevant influence on health behavior. This study was conducted to test the validity and reliability of a questionnaire to investigate fever concepts among German and Turkish mothers living in Germany and to develop hypotheses on important correlations between cultural background and specific perceptions, explanations, fears, and measures taken when confronted with fever. We conducted 50 face-to-face interviews with Turkish and German mothers and 40 re-interviews by telephone. Validity of items was tested by discussion of videotaped interviews, cognitive interviewing and problem coding. To determine the reliability of items, Cohen's kappa was calculated. We found good results for validity and moderate to excellent results for reliability. The results of this pilot study indicate a relevant influence of the cultural background on the perception, explanation and treatment of childhood fever by mothers. However, a larger sample is required to adjust for educational and socioeconomic status.