Background <p>Prostate cancer (PCa) remains a significant public health concern in Kenya, with high morbidity and mortality rates. Despite this, routine screening is not widely practiced, and many men seek medical care only when symptoms appear at advanced stages, resulting in poor outcomes. This study aimed to identify the factors influencing prostate cancer screening uptake—including socio-demographic characteristics, healthcare service factors, and health-seeking behavior among men aged 30–64 years in Mukuru informal settlement.</p> Methods <p>Analytical cross-sectional mixed-methods design was employed, integrating both quantitative and qualitative approaches. Primary data were collected through semi-structured questionnaires, key informant interviews, and direct observation. Secondary data were obtained from health facility records, patient files, and Ministry of Health (MoH) reporting tools for non-communicable diseases. A total of 200 male respondents aged 30–64 years were sampled from Mukuru informal settlement. A total of 200 men were sampled for the quantitative survey, while additional key informant interviews were conducted to generate qualitative insights which included facility In-charges, clinicians, lab technicians, health records officers and community health assistance (CHA) totaling 36 key informants that were interviewed. Quantitative data were analyzed using descriptive statistics, Chi-square tests, and binary logistic regression with a significance level of <i>p</i> &lt; 0.05, while qualitative data were analyzed through deductive thematic analysis.</p> Results <p>Of the 200 men sampled, 46.5% (93/200) were below 40 years, 28.5% were aged 30–34 years, and only 6.5% were aged 60–64 years. Screening uptake remained extremely low, with only 3.5% ever screened. Pearson’s Chi-square test showed significant associations between screening uptake and awareness of screening methods (<i>p</i> = 0.001), knowledge that prostate cancer is manageable (<i>p</i> = 0.008), and knowledge of risk factors (<i>p</i> = 0.001). Logistic regression further confirmed these associations, with awareness of screening services (OR = 19.0; 95% CI 8.89–40.63) and knowledge of manageability (OR = 13.57; 95% CI 6.30–29.24) strongly predicting screening uptake. Moreover, most respondents (80.5%) were married and had received formal education. The majority were self-employed (50.5%) or casual laborers (30%), and over half (52.5%) lived near a public healthcare facility. Qualitative analysis revealed consistent themes, including limited availability of screening services, financial barriers, poor health-seeking behavior, low awareness, and inadequate policy implementation.</p> Conclusion <p>Prostate cancer screening uptake among men in Mukuru informal settlement remains very low, and is shaped by a combination of individual awareness, knowledge of screening methods, and health-system constraints. The study demonstrates that improving early awareness, strengthening service availability, and addressing access barriers are essential for enhancing screening uptake. Targeted interventions focusing on education, affordability, and service delivery could substantially improve future screening practices in similar low-resource settings.</p>