The Animated Triangles Task (AT) is commonly used to measure Theory of Mind (ToM). AT can be scored by clinicians based on participants' verbal responses (AT-verbal) or using a multiple-choice paradigm (AT-MCQ). This study aimed to evaluate the validity of the less time-consuming AT-MCQ. To do this, we examined agreement and correlations between the AT-MCQ and the original AT-verbal scores in 1546 adolescents from a population-based sample. As a supplementary analysis of known-groups validity, we examined if AT-MCQ was as sensitive as AT-verbal in detecting ToM-limitations in 54 adolescents with autism spectrum disorder (ASD), using register-data. The agreement between AT-verbal and AT-MCQ varied markedly across test items. Scores on the two scoring methods were weakly correlated. Both scoring methods weakly detected differences between adolescents with and without ASD in this population-based sample. Most participants had appropriate responses on both AT-MCQ and AT-verbal, which yielded overall acceptable agreement. However, the feasibility of using either scoring methods to measure ToM-limitations in adolescents from the general population is questionable.