This study employs a Logistic Smooth Transition Regression to model the impact of economic reforms in Vietnam from 1985 to 2006 in three economic areas: the agricultural sector, industrial sector and service sector. We examine the response of both GDP and labor productivity to the reforms in each of these sectors. While our results suggest that allowing for structural breaks in GDP and labor productivity is preferred to either a trend stationary or a unit root process, they also suggest evidence of a positive impact of reforms on GDP growth. Estimated results of parameter γ from three models indicate that the speed of the transition of the agricultural sector between the initial and final states was faster than the others. It implies that reforms in agriculture succeeded in encouraging people to work and also in quickly stabilizing the macro economy. Finally, our results also suggest that the different reform policies undertaken had different impacts on the GDP growth of each sector in Vietnam.