This study aims to test the effectiveness and cost-effectiveness of two different strategies of home-delivered HPV self-sampling, in comparison to the standard of care strategy, to increase adherence to cervical cancer screening. An experimental and population-based study will be implemented at three primary healthcare centers located in the Western Porto region: Cedofeita, Garcia de Orta, and Prelada. Eligible women will be randomized into a control group or an intervention group. The control group will correspond to the standard of care (invitation to screening in a clinical setting). The intervention group will be randomized into two subgroups: 1) a directly mailed group that will receive a self-sampling kit at their home addresses by post; 2) an opt-in group that will receive an invitation at home asking if they want to receive a self-sampling kit, with a pre-paid envelope to return the answer to this question. Women who answer yes will receive the self-sampling kit at their home addresses by post. Self-sampling samples will be subjected to HPV genotyping. In parallel, high-risk HPV positive women will be called in by their family doctors to undergo screening in a clinical setting so that they can continue their clinical follow-up in the conventional pathway.