To investigate the relationship between the Responsible Parenthood and Reproductive Health Law in the Philippines and women's unmet needs for contraception. The study involved data on women aged 18 to 49years from the 2013 (n = 14053), 2017 (n = 21 835) and 2022 (n = 24 253) Philippine Demographic and Health Surveys. The Responsible Parenthood and Reproductive Health Law was enacted in 2012, but not fully implemented until 2017. Survey-weighted logistic regression was used to estimate the association between variables and an unmet need for contraception, and the probability that women in different wealth quintiles would have an unmet need. We observed a persistent gap in unmet needs between women in the lowest and highest wealth quintiles in all years. In 2013, the odds of unmet needs for women in the lowest quintile compared with those in the highest were 1.288 (standard error (SE): 0.124); and in 2022, it was 1.287 (SE: 0.113). Nevertheless, the weighted proportion of women with unmet needs declined between 2013 and 2022; in the lowest wealth quintile, it fell from 18.4% to 10.6%. Moreover, the probability of having an unmet need declined across all wealth quintiles between 2013 and 2022; the largest decline was from 0.146 (95% confidence interval, CI: 0.131-0.162) to 0.088 (95% CI: 0.079-0.098) in the lowest quintile. The unmet needs for contraception declined substantially following implementation of a new reproductive health law. However, there was a persistent gap in unmet needs between the lowest and highest wealth quintiles.