Abstract Purpose To analyse the Health-Related Quality of Life (HRQoL) at diagnosis of patients with prostate cancer (PCa) according to tumour extension and urinary symptomatology and to explore factors associated with HRQoL. Methods 408 Controls and 463 PCa cases were included. Eligibility criteria were a new diagnosis of PCa (cases), 40–80 years of age, and residence in the participating hospitals’ coverage area for ≥ 6 months before recruitment. HRQoL was evaluated using the 12-Item Short-Form Health Survey, Mental (MCS) and Physical Component Summaries (PCS), and urinary symptoms with the International Prostate Symptom Score. HRQoL scores for all PCa cases, according to tumour extension and urinary symptoms, were compared with controls. In addition, information about lifestyles and comorbidities was collected and its association with low HRQoL (lower scores) were explored using logistic regression models. Results Overall cases had similar PCS score, but lower MCS score than controls. The lowest standardised scores for both PCS and MCS were reached by cases with severe urinary symptoms and a metastatic tumour [mean (SD); PCS: 41.9 (11.5), MCS: 42.3 (10.3)]. Having “below” PCS and MCS scores was associated with the presence of three or more comorbidities in the cases [aOR = 2.86 (1.19–6.84) for PCS and aOR = 3.58 (1.37–9.31) for MCS] and with severe urinary symptomatology [aOR = 4.71 (1.84–12.08) for PCS and aOR = 7.63 (2.70–21.58) for MCS]. Conclusion The mental dimension of HRQoL at diagnosis of patients with PCa was lower than in controls, especially for cases with severe urinary symptoms and a metastatic tumour. Comorbidities and urinary symptoms were variables associated with the HRQoL of PCa cases.