Introduction: Tanzania is among of the African countries with high maternal and child mortality rates and fast growing population. It also has high fertility rate and a huge unmet need for family planning. Contraceptive use reported to avert more than 1 million maternal deaths in Sub-Saharan Africa due to decline in fertility rate and thus help to achieve MDG 4 and 5. Therefore, this study aimed to determine factors influencing modern contraceptive use among women aged 15 - 49 years in Tanzania. Methods: This was a secondary analysis of Tanzania Demographic Health Survey (TDHS), 2010. A total of 475 clusters (urban and rural) composed of 9663 households were selected. During the survey, a total of 10,139 women aged 15 - 49 years were interviewed about sexual and reproductive matters using a standardized questionnaire. We restricted our analysis to married/cohabiting women (n = 6412) responded for in individual records and domestic violence (n = 4471). Univariate and multiple logistic regression analyses were performed using Stata version 11.0. Odds ratios with 95% confidence intervals for determinants of modern contraceptive use were estimated. A P value of 5% (2 tails) was considered statistically significant. Results: Women empowerment (OR = 1.4; 95% CI: 1.13 - 1.63), male-female age difference of less or equal to nine (OR = 1.6; 95 CI: 1.01 - 2.66), and advice given at health care facilities on family planning (OR = 1.6; 95 CI: 1.37 - 1.96) were predictors of modern contraceptive use. Woman sexual violence was not associated with modern contraceptive use. Conclusions: The predictors of modern contraceptive use in our study correspond with previous studies in low and middle income countries. Women empowerment, male-female age difference, and child desire were important predictors for modern contraceptive use. This highlights the need to promote contraceptive use among women of reproductive age.