This article investigates Vietnam’s agricultural trade specialization on the world markets by employing the Lafay index (LFI). The dynamics of LFI values from 1997 to 2014 are analyzed in three ways: OLS method, Markov matrix, and trend analysis. The results indicate that Vietnam is highly specialized in the crop and fishery sectors, while it is de-specialized in the livestock and processed-food sectors. The highly specialized sectors tend to decrease the degree of specialization, and the de-specialized sectors increase the degree of specialization. However, the general specialization pattern is not strictly obvious. The impact of the crisis in 2008 is also unclear.