This work aimed at constructing and validating a scale in order to assess the interpersonal dimensions of dysfunctional perfectionism in children. Two studies were conducted. The first one proposed a preliminary pool of items submitted to expert and child judgment in order to assess its clarity and theoretical adequacy. The second one aimed to analyze the psychometric properties of the resulting scale (n = 849). Exploratory and Confirmatory Factorial Analyzes denoted the existence of two distinguishable factors: Socially Prescribed Perfectionism (ω = .84) and Other-Oriented Perfectionism (ω = .83). The final version of the scale included 16 items (ω = .89). It is concluded that interpersonal dimensions of the new scale of maladaptive perfectionism in children work properly and could be of great relevance to expand the understanding of this construct during childhood.