International integration and globalization are among the decisive factors in increasing the demand for knowledge of foreign languages. International exams and tests provide the opportunity to confirm proficiency in foreign language communicative competencies. In particular, Russian as a foreign language can be difficult even for foreigners who speak it confidently. The object of scientific interest is lexical interference as a result of the imposition of the Russian and Spanish systems on each other due to the erroneous identification of units of the lexical fund by native speakers of Spanish, due to a lack of knowledge about accepted language norms and lexical compatibility, as well as due to insufficient methodological support for the maintenance and development of productive type of speech activity. Writing is one of the most difficult tasks when preparing for the TORFL, as it requires a large vocabulary and the ability to select and find words for a certain style and other speech conditions. Our study provides an analysis of written statements on various topics by foreign students, native Spanish speakers, of high levels in order to determine interference features at the lexical level. Based on the results obtained, primary methodological recommendations are provided for overcoming the issue under consideration and the development of lexical-semantic competencies of the target audience.