BackgroundPatient preference for the choice of treatment modality for prostate cancer has increasingly gained attention.ObjectiveTo assess the impact of client‐oriented decision on long‐term mortality, disease progression and biochemical failure compared with standard treatment protocol (TP).MethodsWith data from a Finnish multicentre, randomized controlled trial with two arms [104 in the enhanced patient participation (EPP) arm and 106 in the TP arm], disease‐specific and disease‐free survival, biochemical failure with elevated prostate‐specific antigen (PSA) level and disease progression were compared between the two arms using Wilcoxon test and also Cox proportional hazards regression model.ResultsPatients in the EPP arm had a higher risk of death by 37% [HR, 1.37 (0.87–2.17)] compared with those in the TP arm. Patients in the EPP arm were at increased risk of having biochemical failure by 14% [HR, 1.14 (0.72–1.79)] and for having disease progression by 2% [HR, 1.02 (0.61–1.70)] compared with those in the TP arm. All the differences were non‐significant.ConclusionsPatients actively involved in the choice of treatment had higher risk of prostate cancer death but only slightly increased risk of biochemical failure and clinical disease progression. These findings would provide a good reference when patient autonomy for the choice of treatment modality is addressed.