The article analyzes the category of otherness in the work of Octavio Paz and Antonio Machado, which occupies a central place in the system of philosophical and aesthetic ideas of both poets. Based on the study of key works of A. Paz and A. Machado the author proves the adjointness such of concepts as «otredad» and «heterogeneidad», revealing the basic principles of interaction between Myself and Others. In addition, in the article the connection between theoretical propositions which postulated by both authors, and its realization in their poetic texts is traced.