The Independent-Interdependent Problem-Solving Scale is based on Cross et al.’s conceptualisation of relational-interdependent self-construal. The IIPSS provides a relatively context-free measure of people’s tendencies to solve problems independently or with the help of others. Because previous investigations have not provided extensive evidence for the reliability and validity of the IIPSS, the current research aimed to test the psychometric properties of this novel measure. Investigations of four student samples (combined N = 1157) and one sample comprised of academic researchers (N = 198) generally supported the reliability and validity of the IIPSS. Exploratory factor analysis of IIPSS items yielded a single factor structure. However, confirmatory factor analyses did not demonstrate good model fit for the one factor solution and instead yielded good model fit for two underlying factors. The IIPSS showed adequate test–retest reliability and predicted positive associations with social personality traits. It also showed no significant associations with measures of demand characteristics and social desirability. Future research needs to be undertaken to further assess the factor structure and address shortcomings of the present research such as utilising objective data in addition to self-reports to assess the scale’s validity.