Chile is one of only four countries in the world where there is no explicit legal exception to prohibitions on abortion, and where the criminalisation of abortion endangers women's health and may be misaligned with public opinion. In this study we explored attitudes towards the legalisation of abortion and differences in levels of support across time. Among Chilean women in 2009 and 2013, we examined: (1) an additive index indicating support for legalisation of abortion in several situations and (2) support for each situation separately. We investigated the demographic characteristics associated with support for legalisation using multivariate regression. Over 70% of women supported the legalisation of abortion in cases of risk to the woman's life, rape and foetal malformation, and support was higher in 2013 compared to 2009 (β = 0.28; 95% CI: 0.12, 0.44). Women with increasing education and those attending church services less frequently were more likely to support the legalisation of abortion (β = 0.27; 95% CI: 0.11, 0.43), while those affiliated to a religion other than Catholicism (β =  - 0.32; 95% CI:  - 0.48,  - 0.16) were less likely to do so. Our study is the first to examine public opinions on abortion in Chile and differences in levels of support across time periods. Results indicate that current policies may not reflect trends in public opinion.