Palmitic acid (PA) is a major fatty acid, derived from diet and endogenous production, which is being linked to inflammation. While such actions of PA at the level of the testis remain difficult to examine, we reasoned that studies in human testicular cells may be instructive. Human testicular peritubular cells (HTPCs) can be isolated from men and cultured. They have contractile properties but also produce IL6, express the inflammasome NLRP3, and via glia cell line derived neurotrophic factor (GDNF), they contribute to the spermatogonial stem cell niche. We found that PA at 100 μM significantly increased the levels of IL6, while NLRP3 or the related IL1beta were not affected. The contractility marker CNN1 and the growth factor GDNF were likewise not affected. ELISA studies confirmed the stimulatory PA actions on IL6. Hence, PA derived from diet and/or endogenous sources may be able to foster a pro-inflammatory milieu in the testis. A possible link of these results to diet and high fat intake and obesity is indicated by the about 12 fold elevated testicular levels of IL6 in testes of obese rhesus monkeys (n=3), fed with a Western Style diet. They had elevated 2 - 5 fold increased body fat and increased circulating triglyceride levels. Further consequences of PA 38 and obesity for testicular functions remain to be evaluated.