The most promising direction in the treatment of chronic prostatitis is the use of medicinal plants and preparations based on them, which contain natural compounds with a broad spectrum of pharmacological activity: anti-inflammatory, antimicrobial, reparative, immunomodulatory, hormone-regulating, antisclerotic, etc., and which can provide a complex therapeutic effect on the course of chronic prostatitis. A promising raw material in this direction is Tribulus terrestris L., a herbal preparation traditionally used to treat erectile dysfunction and atherosclerosis. This experimental work aims to study the anti-inflammatory activity of a thick extract of the Tribulus terrestris grass (freed from fruits) on the models of carrageenan and zymosan inflammation in rats. In the models of carrageenan and zymosan edema in rats, a thick extract of Tribulus terrestris L. in doses from 50 mg/kg to 200 mg/kg shows anti-inflammatory activity, the efficacy of which in the dose range of 150-200 mg/g in the initial stages of carrageenan inflammation is not inferior to sodium diclofenac at a dose of 8.0 mg/kg, and in the initial stages of zymosan inflammation, respectively, before the reference drug corvitin at a dose of 10 mg/kg. It indicates the anticyclogenase and antilipoxygenase properties of this thick extract.