To assess the microbiological quality of frozen seafood products onboard deep-sea fishing vessels, samples of three species Sepia officinalis, Solea vulgaris and Parapenaeus longirostris were taken during the landing of these marine products at the port of Agadir, Morocco. All samples were analyzed for Aerobic Germs at 30°C, Staphyloccocus aureus, Enterobacteria, Coliforms at 30°C, Coliforms at 44°C, Escherichia coli, Anaerobic sulphitoreducer germs, Listeria monocytogenes, and Salmonella spp. Absence of Salmonella and L. monocytogenes is noted in all samples of the three species, (0 CFU/25g). For S. officinalis, S. vulgaris and P. longirostris, the concentration of E. coli, Enterobacteria and Coliforms at 30°C counts were all below the regulatory threshold (10 CFU/g). S. aureus was less than 100 CFU/g for the three species. Our results also showed that the concentration of Coliforms at 44°C and the anaerobic sulphitoreducer germs (ASR) were less than 10 CFU/g for the three species. Aerobic germs at 30°C counts ranged between 40 CFU/g and 1100 CFU/g in S. officinalis, between 45 CFU/g and 5000 CFU/g in S. vulgaris and between 55 CFU/g and 3800 CFU/g in P. longirostris. These results are below the thresholds recommended by national and international regulations, which are 105 CFU/g, 106 CFU/g and 107 CFU/g respectively for P. longirostris, S. officinalis and S. vulgaris. This study shows that the seafood products landed by the vessels considered in this study are of good microbiological quality and show no contamination.