This study examines trend and determinants of unmet need for family planning (FP) among currently married women and sexually active unmarried women of reproductive age 15–49 in Nigeria over a period of 10 years (2003–2013). Data from three consecutive Nigeria Demographic and Health Surveys (2003, 2008 and 2013) were analyzed. The results show that the unmet need for FP declined between 2008 and 2013 to a level less comparable with the situation in 2003. The significant determinants of unmet need for FP included age, marital status, education, religion, current work status, decision-making on spending personal earnings, gender of household heads, household wealth status, number of living children (including current pregnancy), rural-urban residence, home visit by FP workers and recent exposure to FP messages via mass media. It is therefore necessary that FP programmers continue to develop specific responses that address the barriers to contraceptive use.