The main objective of this study was to evaluate the collocational errors made by Russian learners of Persian using Corpus Linguistics methodologies. To achieve this goal, a small yet detailed learner corpus comprising Russian and Ukrainian intermediate learners of Persian as a second language was compiled at Saadi Foundation and annotated using the CATMA corpus tool. Additionally, the Sketch Engine corpus software was employed for the analysis of collocations and concordance lines. Selinker’s classification was utilized to analyze and categorize the errors identified in the learner corpus. The findings of the study revealed that learners exhibited difficulties in producing and utilizing collocations accurately in their acquisition of Persian as a second language. These errors indicate areas where learners may require additional support and instruction to enhance their collocational competence. The implications of this research are expected to be practical and beneficial for various stakeholders, including educators and researchers in the fields of Persian language instruction, error analysis, Corpus Linguistics, and Learner corpora.