Background <p>Cervical cancer is preventable through effective screening programmes, yet adherence remains suboptimal in Portugal. This study aimed to explore the reasons for non-adherence to cervical cancer screening, including socio-demographic influences and women’s perceptions, to inform targeted interventions.</p> Methods <p>A cross-sectional study was conducted among women aged 25–60 years identified as non-adherent to cervical cancer screening within a primary care unit in northern Portugal. Participants were randomly selected and recruited via telephone. Data collection included socio-demographic characteristics, screening history, reasons for non-adherence, and knowledge of cervical cancer.</p> Results <p>Among 262 participants, 43.9% were not compliant with recommended screening intervals. The main barriers identified were lack of a healthcare provider’s prescription (34.8%), personal discomfort or forgetfulness (17.4%), low health literacy (15.7%), and limited access to facilities (14.8%). Adherence was positively associated with higher education, access to private healthcare, and positive health self-perception, while lower education and overconfidence in symptom recognition were linked to reduced adherence.</p> Conclusion <p>Non-adherence to cervical cancer screening reflects a complex interplay of systemic, educational, and personal factors. Addressing these requires improved provider–patient communication, targeted health literacy initiatives, and enhanced service accessibility. Tailored public health strategies are crucial for reducing disparities and supporting national and WHO cervical cancer elimination goals.</p>