The aim of this article is to assess the maturity level of girls in the Lubusz Voivodeship depending on the living environment, parents’ education, the number of children in the family and the standard of living. The material consists of the results of research conducted among 10–18 year-old girls (after menarcheal age) in 2015–2017 in selected primary, middle and upper secondary schools. A total of 3,525 girls were examined. The data were collected by means of a diagnostic survey, using the retrospective method, the research technique was a questionnaire, and the research tool was a questionnaire. Basic statistical characteristics for each variable, one-way analysis of variance, significance level of differences and a test of independence were calculated. The questionnaire was also validated with the reliability coefficient of 0.68, which qualifies it for use in cross-sectional studies. As a result of the analysis of the material, it was found that the following girls matured the earliest those from medium-size and small towns, daughters of fathers with higher or vocational education, daughters of mothers with higher education, girls growing up in families with one child, girls from the richest families.