MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in a variety of biological processes. Studies of miRNAs in mammals suggest that many are involved in lipid metabolism and adipocyte differentiation, but little is known about miRNA expression profiles during chicken adipogenesis. In this study, the Solexa sequencing approach was used to sequence a small RNA library prepared from Arbor Acres broiler pre-adipocytes, and more than 10⁶ short sequence reads were obtained. From these, 159 known chicken miRNAs and 63 novel miRNAs were identified using a bioinformatics approach. Fifty-nine of these miRNA genes were further organized into 27 compact miRNA genomic clusters, and 34 new chicken mirtrons were also discovered, among which there were 27 mirtron candidates. These findings should serve as a foundation for future research on the functional roles of miRNAs in chicken adipocyte differentiation.