Summary.A new sentence‐completion test has been constructed in order to explore further the development of interpersonal relationships in adolescence, following an earlier study based on a different type of projective test. The responses of three different age groups of adolescent girls from a grammar school in a working‐class area are compared, and the results indicate that in the majority of interpersonal situations there are important differences between age groups, most of which are consistent with those reported in the previous study. The results support the view that a sentence‐completion test is an appropriate and significant means of studying interpersonal develo