Socially prescribed perfectionism (SPP) is often considered as a key risk factor for disordered eating (DE). However, current conceptualizations of SPP largely assume that this perfectionism pressure is non-specific (i.e., a global pressure), despite research indicating that for females experiencing DE, female-dominated groups impose this pressure (as a perceived norm). Furthermore, this relationship may be mediated by a negative reaction to this pressure, in the form of impulsivity (or negative urgency). To date, no research has investigated whether the relationship between SPP and DE is mediated by negative urgency, nor has there been research clarifying how in-group identification relates to DE, independent of SPP and negative urgency. To address these gaps, we assessed these variables in 147 female dieters (M  = 25.12 years, SD = 3.08) using a cross-sectional design. Consistent with our hypotheses, negative urgency fully mediated the link between female-based SPP and disordered eating, while female-based in-group affect (identification) was predictive of disordered eating (although the latter relationship was not sustained in a multiple regression model). These findings suggest that the SPP from other women may relate to DE through increasing negative urgency, and that the link between in-group (female) affect and DE may be better explained by SPP's link to DE.