Unwanted pregnancy constitutes a huge embarrassment for parents and community, especially when it concerns adolescent girls of school age. Many factors put them at risk and consequently the need for sex or reproductive health education. This study aims to determine the risk factors associated with unwanted pregnancy and sex education needs of adolescent school girls in Amassoma community, Bayelsa state. A descriptive cross-sectional survey design was utilized. Using a multistage sampling technique involving 3 steps and by simple random sampling, 170 respondents were selected. Data was collected using a self-structured close-ended questionnaire and questions analysed with statistical package for social sciences (SPSS) version 21 in the form of frequency distribution tables, and percentages. The results of the study indicate that a high number of 146(89%) of the respondents are linked with high-risk factors towards unwanted pregnancy. Given that the socio-demographic variables and overall risk factors for age, grade level, religion, marital status, residence and guardians socio-economic factors were all statistically not significant respectively (p =0.306; p =0.972, p =0.725; p = 0.211; p = 0.837 and p = 0.211). Similarly, a high rate of reproductive education needs 121(73.8%) among respondents on sex education needs were not met. Evidenced from analysis of results the government, NGO's, schools, hospitals, the community, families and parents are recommended to pay keen attention to the risk factors and reproductive or sex education needs of the adolescent girls.