This work aims at evaluating encapsulation and controlled release of vitamin B2 from alginate/chitosan nanoparticles. Ionotropic polyelectrolyte pre-gelation was used as production method being chitosan and alginate used as main materials. Nanoparticles were characterized in terms of average size, polydispersity index (PDI), zeta potential and vitamin entrapment efficiency. The average size for alginate/chitosan nanoparticles was 119.5??49.9nm for samples without vitamin B2 and 104.0??67.2nm with the encapsulation of vitamin B2, presenting a PDI of 0.454??0.066 and 0.319??0.068, respectively. The nanoparticles showed encapsulation efficiency and loading capacity values of 55.9??5.6% and 2.2??0.6%, respectively. Release profiles were evaluated at different conditions showing that the polymeric relaxation was the most influent phenomenon in vitamin B2 release. In order to study their stability nanoparticles were stored at 4??C being particles sizes and PDI evaluated during 5 months showing the results that vitamin B2-loaded nanoparticles are more stable (in terms of size and PDI) than nanoparticles without vitamin B2.