Teacher's self-efficacy is a relevant judgement of self-belief by teachers. Studies reveal inverse response bias of teachers' self-assessment. Parallel item presentation can be used as a method to reduce such distortions. The major goal of this study was to develop and verify such a measure of parallel item presentation in order to compare self-efficacy of qualified and out-of-field PE teachers. Therefore out-of-field and qualified PE student teachers (N = 68) were randomised into two groups. They responded to 14 self-efficacy items related to classroom subjects and PE teaching. One group of out-of-field (n = 17) and qualified (n = 18) PE student teachers was presented with the items in parallel so that they could compare classroom and PE teaching items. For the other group of out-of-field (n = 11) and qualified (n = 22) PE student teachers, the items were presented sequentially so that no direct comparison was possible. Data was analysed using nested ANOVA. The results reveal that with a dimensional item comparison, out-of-field PE teachers have a significantly lower self-efficacy in PE than qualified PE student teachers (p = 0.006, [partial eta-squared] = 0.18). Without comparison, there is no significant difference. The method of parallel item representation can thus contribute to the reduction of inverse response bias.