In RNA silencing, small RNAs produced by dicer mediate target repression guided by RNA induced silencing complex (RISC). To effectively mediate this response, one or more proteins are employed at each stage. In the present study, we investigated HADHA, a new component in the human RNA silencing machinery. Immunoprecipitation analysis revealed that, HADHA associates with dicer complex and immunohistochemical studies confirmed its co localization with Dicer in the cytoplasm. Further, over expression of HADHA resulted in higher abundance levels of mature miRNA against a reduction in respective precursor levels and vice versa in HADHA knocked down cells. These findings suggest an auxiliary role for HADHA in miRNA biogenesis and help in better understanding of molecular mechanisms underlying RNAi pathway in mammals. (C) 2015 Elsevier Inc. All rights reserved.