The paper describes and analyses two language systems, English and Serbian, particularly one segment of the grammar of both languages – nonfinite relative clauses. The methods used are contrastive analysis, description and classification.Both English and Serbian nonfinite relative clauses function as postnominal modifiers. They are contrasted with the purpose of determining their similarities and differences. English nonfinite relative clauses are constructed using all nonfiniteverb forms (infinitive, -ing and -ed verb forms) in active and passive voices and progressive, perfect and simple aspects, whereas Serbian nonfinite relative clauses are constructed using radni glagolski pridev (active participle) and trpni glagolski pridev (passive participle). These two Serbian nonfinite verb forms are limited in their use in nonfinite relative clauses depending on various grammatical aspects. The differences between the uses of English and Serbian nonfinite relative clauses are identified concerning the frequency of use and variety of meanings.