Whilst a range of studies address the aquaculture livelihoods in southern Vietnam’s Mekong Delta, the role of aquaculture in northern Vietnam remains less described. We, therefore, conducted interviews with 199 households in the two northern provinces Quang Ninh and Nghe An in 2014 to analyse the dependence on aquaculture in these two provinces and amongst farmers specializing in shrimp and freshwater fish production, respectively. Further, we tested the ability of different socio-economic variables to explain the observed reliance on aquaculture using an ANCOVA model. The study identifies a substantial reliance on aquaculture of farmers in the study area with at least half of their income generated by aquaculture. Our analyses highlight that the educational background of farmers explain their engagement in aquaculture better than how long they have worked as aquaculture farmers. Freshwater fish farmers were shown to rely less on aquaculture as it is only generating a supplementary income. In contrast, the shrimp farmers are not only those having the highest share of income from aquaculture but also earning their main living from aquaculture. The fact that both shrimp and fish farmers have diverse sources of income shows the unstable or risky nature of aquaculture livelihoods in the study area. Our findings suggest that policies promoting aquaculture should focus on training of farmers whilst acknowledging that a diverse income portfolio increases livelihood resilience to external shocks such as extreme weather events, diseases and fluctuating market prices.