Background: There are few studies which have shown inconsistent results regarding the associations between dietary acid load (DAL) and the risk of cancer. This study aimed to examine the association between DAL and prostate cancer (PC) risk among Iranian population. Methods: One hundred and twenty participants (60 controls and 60 newly diagnosed PC patients) engaged in a hospital-based case-control study. Validated 160-items semi-quantitative food frequency questionnaire (FFQ) was used to assess usual dietary intakes. DAL was calculated using potential renal acid load (PRAL) and the net endogenous acid production (NEAP). Multivariate logistic regression was used to estimate the odds ratios. Results: Both PRAL (OR=5.44; 95% CI= (2.09-14.17)) and NEAP (OR=4.88; 95% CI= (2.22-13.41)) were associated with increased risk of PC in crude model. After adjusting for potential confounders (energy intake, smoking, physical activity, ethnicity, job, education, and some drugs usage) compared to the first category, being in the third category of PRAL (OR=3.42; 95% CI= (1.11-8.65)) and NEAP (OR=3.88; 95% CI= (1.26-9.55)) was associated with increased risk of PC. Conclusions: Our findings suggest that DAL could be associated with increased risk of PC. However, further prospective studies with larger sample sizes and longer durations are needed to confirm these findings.