The Satisfaction with Family Life Scale (SWFLS) is a measure of a person’s satisfaction with their family life as a whole that has been used in different cultural contexts. However, its internal structure and factorial invariance have not been investigated simultaneously in culturally different samples from America and Europe. The current study aims to evaluate the internal structure and factorial invariance of the SWLFS in adolescents from Peru and Portugal, through a multi-group confirmatory factor analysis. The study was conducted on 439 adolescents from Peru (N = 232; Ageaverage = 15.50, S.D. = 0.65) and Portugal (N = 207; Ageaverage = 16.16, S.D. = 0.81). First, the confirmatory factorial analysis for each group was carried out, followed by the multi-group confirmatory factorial analyses. Results indicated that the one-factor structure of the SWLFS presents a good adjustment to the data, in addition to an adequate internal consistency. Moreover, the presence of configural, metric, scalar and strict invariance is demonstrated across culturally different samples. The SWFLS is a brief and valid measure of satisfaction with family life that is useful for intercultural comparisons between samples of adolescents from Peru and Portugal.