Despite its documented benefits, contraceptive use among adolescents remains low, particularly in low-and middle-income countries. This study aimed to decompose the main factors contributing to the changes in contraceptive use among adolescent girls in Zambia over the period 1996 to 2014. Data on adolescent girls aged 15-19 years from Zambia Demographic and Health Survey data were analysed using multivariate decomposition analysis of change. Stata 15/MP (Stata-Corp LLC) was used for analysis, at a 95% confidence level. A p-value of 0.05 was used to determine statistical significance. The sample included 9,072 adolescent girls. Contraceptive use increased by 3% from 7.6% in 1996 to 10.6% in 2013/14. Change in modern contraceptive use among adolescents was mainly due to differences in coefficients (changes in population behaviour). Increases in age contributed to the change in contraceptive use, resulting in 2.94% and 9.33% increases for 17- and 18-year-olds respectively. Marriage or living with a partner contributed the largest change (44%) while living in a rural area accounted for approximately 20%. Interventions targeting improving contraceptive use in adolescents should be responsive to the needs of various age groups, places of residence, and educational levels for maximum benefits.