The article discusses occasional words presented in the correspondence of B. L. Pasternak, which covers a half-century period. Many researchers turned to B. Pasternak’s oeuvre, poetic, prosaic, including epistolary, but did not consider individual author’s innovations in the correspondence. The letters of B. Pasternak are addressed to various people (relatives, friends, colleagues) with whom the poet was in various kinds of relations. In relation to individual word creation, there are a number of terms in modern linguistic science (innovation, poetic neologism, occasional word (occasionalism), potential word), among which the term occasionalism is most preferable. Occasional words form groups by parts of speech. These are substantive, adjective, verbal, adverbial groups. We also consider ways of forming new words, the most productive of which is an affi xal (morphological) one. Occasionalisms in correspondence perform a semantic intensifying-distinguishing function, they allow you to express an idea more accurately, to convey the mood and state of the writer. The methods of using word-formation means in correspondence refl ect the originality of the poet’s world. In Pasternak’s epistolary genre, occasionalisms act as a style-forming tool; their use is a hallmark of the individual style of the author.