Little is known about the significance of inflammation in neoplastic colon polyps: tubular, tubulovillous, and villous polyps/adenomas (TVPs) and hyperplastic/serrated polyps (HSPs). We undertake this study to ascertain the significance of acute and chronic inflammation in neoplastic polyps. Eighty-one consecutive, randomized TVPs and fifty-four randomized HSPs accessioned in the UCHC surgical pathology laboratory were selected for final analysis. The TVPs display increased acute and chronic inflammation compared to normal and adjacent non-dysplastic colonic mucosa. Adenoma size correlates with degree of acute and chronic inflammation. TVPs show increased overall acute and chronic inflammation compared to HSPs of the same size. This difference was statistically highly significant (p<.001). The number of adenomas exhibiting high grade dysplasia was insufficient to evaluate the relationship between polyp inflammation, polyp size, and degree of dysplasia. The HSPs showed significantly lower incidence and severity of acute and chronic inflammation compared to the TVPs. No correlation was seen in the HSP group between polyp size and acute or chronic inflammation. The prevalence of IBD was higher in patients with HSP showing acute inflammation than in the general population, but this statistic may be skewed by the low overall incidence of acute inflammation in the HSP group.