The influence of the peer group on young people’s achievement motivation has been highlighted in the literature as an area that needs examination (e.g., Harwood & Swain, 2001). To this effect, a new measure of youngsters’ perceptions of the peer motivational climate (Peer Motivational Climate in Youth Sport Questionnaire; PeerMCYSQ) was developed and tested across three studies. In Study 1, exploratory and confirmatory factor analyses (CFA) with 431 athletes between the ages of 11 to 16 years suggested that the PeerMCYSQ had 6 factors that could also be subsumed into 2 higher order factors (Task-Involving climate: improvement, relatedness support, effort; Ego-Involving climate: intra-team competition, normative ability, intra-team conflict). In Studies 2 and 3 the 6-factor solution and the corresponding hierarchical one were tested using CFA with two independent samples (N = 606 and 495, respectively) of similar age. The results showed that the 6-factor model was problematic and that a 5-factor solution should be preferred instead. Further support to the 5-factor model was provided with hierarchical and multilevel CFAs. Suggestions for further research on peer motivational climate are discussed.