BACKGROUND: The stress experienced by parents in fulfilling their parental role has consequences for couple dynamics, parent-child interactions, and the mental health of parents. However, studies on the psychometric properties of the PSI-SF, particularly among Latin American parents, are scarce. Therefore, this study aims to evaluate the psychometric properties of the Spanish version of the Parenting Stress Index-Short Form (PSI-SF). METHODS: The participants were Peruvian mothers and fathers with children in early childhood and primary education, with a mean age of 34.4 years (SD = 6.8). The sample was obtained in two phases: 130 participants for the Exploratory Factor Analysis (EFA) and 791 participants for the Confirmatory Factor Analysis (CFA). RESULTS: The study results show a modified three-factor structure of the PSI-SF scale, with adequate fit indices (GFI = .99, AGFI = .99, SRMR = .024, CFI = .98, TLI = .98, RMSEA = .074) and loadings above 0.40. Additionally, the three factors of the scale demonstrated high reliability, with Cronbach's alpha and McDonald's omega values for Parental Distress (α = .94; ω = .95), Parent-Child Dysfunctional Interaction (α = .97; ω = .97), and Difficult Child (α = .94; ω = .94). The scale was also found to be invariant with respect to gender. CONCLUSION: In conclusion, the study results suggest that the modified PSI-SF has adequate psychometric properties and is invariant for assessing parental stress in Peruvian fathers and mothers with children in early childhood and primary education.