Reticuloendotheliosis virus (REV) is an avian retrovirus that causes immunosuppression, growth retardation, and oncogenesis in a variety of birds. REV infection is epidemic in many countries. In this study, we used high-throughput sequencing to identify microRNAs (miRNAs) associated with REV infection. A total of 88 differentially expressed miRNAs were identified in samples collected on days 21 and 28 post-REV infection. Possible target genes of the differentially expressed miRNAs were analyzed. We observed that expression of proapoptotic, proto-oncogene, and carcinogenic cytokine mRNAs was highly upregulated, whereas expression of antiapoptotic cytokine mRNAs was significantly downregulated. Our findings provide a potential link between miRNA expression and the pathogenesis of REV infection.