Background: Family planning improves the health outcomes of mothers and children and reduces pregnancy-related morbidity and mortality, and the economic costs of early pregnancy. Objective: Describe the effect of the age of marriage on contraceptive behaviors. Methods: A cross-sectional study was conducted in a systematic randomly selected five rural primary health care centers in Giza governorate, Egypt to estimate the use of family planning methods among two subgroups using an adapted questionnaire:  female married before 18 Y and that married ≥18 Y. A structured interview conducted among 650 females in reproductive age. Results: Pregnancy number and family size were significantly higher among female married before 18years (3.3±1.9) and (4.8±1.6) versus (2.7±1.5) and (4.4±1.3). Family planning use after first and second child were lower among early married females (84.3%) and (82.5%) versus (85.2%) and (87.4%) of their counterparts married ≥18 Y respectively with no statistically significant differences. The bivariate analysis showed that the likelihood of using a family planning method after the first child was higher among educated women and women with an educated husband than among illiterate women and women with non-educated husband [COR, 2.6; 95% CI,1.5-4.5] and [COR,1.7; 95% CI,1.1-2.9] respectively. Conclusions: Family planning method use was particularly low among females married before 18 and consequently, their family size and their pregnancy number were high. Education is a significant determinant of the age of marriage and of FP use. These factors should be considered during the design of short- term and long-term family planning strategies to effectively increase family planning methods use among early married females especially in conservative contexts.