<p>There was no previous investigation regarding dietary sodium, sugar, and trans fatty acids (TFAs) in relation to odds of male infertility. We aimed to address this knowledge gap by evaluating the association of dietary sodium, sugar, and TFAs with infertility among Iranian men. This was a population-based case–control study on 600 Iranian men aged 20 to 55 yr (300 infertile and 300 fertile men), inhabited in Isfahan in 2024. Cases were picked from newly-diagnosed men seeking fertility care at main infertility centers in Isfahan. A validated 168-item food frequency questionnaire was applied to evaluate sodium, sugar, and TFAs intake over the past year. After adjustments for all potential confounders, men in the highest quartile of sodium had 71% higher odds (OR _{Q4 vs. Q1} = 1.71, 95%CI: 1.05–2.80) and those in the third tertile of TFAs had 78% higher odds (OR _{T3 vs. T1} = 1.78, 95%CI: 1.03–3.05) of infertility compared to their references. Although no significant association was observed between sugar intake and infertility in the total study population, there was a significant association in this regard among men with normal-weight (OR _{Q4 vs. Q1} = 3.47, 95% CI: 1.38–8.72). Unexpectedly, participants with overweight or obesity in third (OR _{Q4 vs. Q1} = 0.54, 95%CI: 0.30–0.98) and fourth quartile (OR _{Q4 vs. Q1} = 0.53, 95%CI: 0.28–0.99) of sugar were less likely to be infertile, compared to the first category. Our study suggested substantial associations between dietary sodium and TFAs and odds of male infertility, with the contribution of overall diet quality. Similar finding was obtained regarding the association of sugar intake and infertility among men with a normal weight.</p>