Objective: To investigate the contribution of angiotensin II towards the process of hepatic fibrosis that is largely due to hepatic stellate cell growth. Methods: Adult rat hepatic stellate cells were cultured and checked for the expression of angiotensin II receptor 1a (AT<sub>1a</sub>) mRNA by RT-PCR and sequence analysis. The effects of angiotensin II were observed on stimulation of hepatic stellate cell growth detected by MTT assays, <sup>3</sup>H-thymidine incorporation and cell count, and collagen synthesis by <sup>3</sup>H-proline incorporation. Results: We demonstrated that cultured adult rat hepatic stellate cells expressed AT<sub>1a</sub> mRNA, and angiotensin II in a concentration-dependent manner stimulated hepatic stellate cell growth at a concentration of 10<sup>–7</sup>–10<sup>–9</sup> mol/l and collagen synthesis at a concentration of 10<sup>–6</sup>–10<sup>–10</sup> mol/l. Also, AT<sub>1a</sub> receptor antagonist, in a concentration-dependent manner, blocked the cell growth from 10<sup>–6</sup> to 10<sup>–8</sup> mol/l and collagen synthesis from 10<sup>–6</sup> to 10<sup>–9</sup> mol/l. Conclusions: The results provided direct evidence that AT<sub>1a</sub> mRNA was expressed in rat hepatic stellate cells and angiotensin II could contribute towards the development of hepatic fibrosis via AT<sub>1a</sub> receptor.