There is much evidence that good management practice is an important factor that positively affects firms' productivity around the world. However, little evidence on effect of management practices on Vietnamese firms has been drawn. This paper provides results of such a study. The quality of management activities is found to be poor and be positively related to the turnovers of firms, the ages of firms, the numbers of employees, investment capital, and human capital. Also, management practice scores change significantly according to the influencing factors including level of competition, degree of decentralization, types of ownership, types of customer firms are serving, advancement of export market, and types of product firms are selling.