Elevated homocysteine (Hcy) concentrations in blood (hyperhomocysteinemia [HHcy]) are a known risk factor for vascular disease and have been associated with fractures, disability, neurological disorders, poor physical function, decline of muscle mass and strength etc. The aim of this study is to analyse the proteolytic activity indexes in rat skeletal muscles with experimental HHcy. HHcy was induced by daily intragastric administration of DL-homocysteine thiolactone (HTL) (200 mg·kg^–1 of body weight) to young and adult male rats for 8 weeks. Blood serum Hcy levels, total proteolytic activity and metal-dependent proteolytic activity, serine proteases activities, total protein and medium molecular-weight substances (MMWS) were estimated. Serum Hcy levels elevated both in young and adult animals with HHcy compared with the control group of corresponding age, thus verifying the HHcy condition. It was shown that HHcy promoted the increase in total proteolytic activity, serine protease activity and metal-dependent one against the background of a more intensive increase in mature animals. Reduced levels of serine proteases were detected in young rats with HHcy, in contrast to adult ones, in which an increase of this indicator was recorded. Elevated MMWS levels in Hcy‑treated rats of both age groups were revealed as compared with control rats. Experimental HHcy is linked with pathological changes in skeletal muscles, which can result in a deceleration of physiological proteolytic remodelling. Understanding the clear mechanisms of such metabolic changes in skeletal muscles requires further studies.