Researchers found that although the overall survival rate increased by 20% from 1990 to 2007, the gap between the wealthiest and poorer patients is widening.
The study of patients in the West of Scotland, which was led by Dr Kashif Shafique of the Institute of Health & Wellbeing at Glasgow University, tracked the outcome of more than 15,000 people.
Patients who lived in the most deprived areas had 10% lower survival at five years from 2003-2007 compared to the patients from the least deprived areas.
Of these, 65% died during the study period compared with 51% in the most affluent areas.
Researchers found that although five-year survival had improved from 58% in 1991-1996 to 78% in 2003-2007, the gap in survival between the wealthiest and poorest patients had increased from approximately 5% to 10%.
Just over half of the 15,292 men included in the study lived in socio-economically deprived areas.
Dr Shafique said: "Previous research has shown that there are socio-economic inequalities in survival of prostate cancer patients but this study revealed that the gap has continued to widen over time.
"Our study also showed that diagnosis of cancers at a younger age or detection of less aggressive disease did not explain the socio-economic inequalities in survival.
"However, further research is needed with information on how advanced prostate cancer is when it is diagnosed in wealthier compared with poorer men."
Prostate cancer is the most common cancer amongst men in Scotland and between 2000 and 2010 incidence increased by 7.4%.