This study evaluates the impact of microcredit on the welfare of the rural households in Vietnam, especially the poor, and investigates the determinants on the accessibility to microcredit programs. Propensity score matching (PSM) method and difference in difference (DID) method are employed to evaluate the impact. The results show that microcredit improves living standard of the rural households via increasing their income and consumption. However, for case of the rural poor, microcredit is found to only improve their consumption but there is no evidence about its impact on their income. This study also found that microcredit programs may not serve the poor households. Such indicators as age, education level, leadership status of household head, household size, dependency ratio, house value, geographic location, facilities of communes are proved to affect the probability of participating in microcredit programs.