This study investigated the determinants of adolescents? pregnancy and access to reproductive health services in Niger Delta region, Nigeria. Two research questions and two research hypotheses were employed. Research design was descriptive survey design. Research instrument was a structured questionnaire. The population comprised of married female adolescents (3,027) in Rivers State. One thousand (1,000) participants were sample through purposive sampling technique. The reliability of the instrument yielded 0.87. The descriptive statistics of simple percentages and mean scores were used to analyze the data while the inferential statistics of simple regression and ANOVA were used to test the hypotheses at 0.05 alpha levels. The study revealed that all the independent variables (poverty and cultural beliefs) were significance correlates of adolescents? pregnancy and access to reproductive health services in Niger Delta region, Nigeria. It was therefore recommended that Ministry and parents must solve the problem of poverty on the access of female adolescents? pregnancy productive health services in Niger Delta, Nigeria. Traditional herbalist and parent should identify the effect of cultural belief on the access of female adolescents? pregnancy productive health services in Niger Delta, Nigeria.