Nanoencapsulation of probiotic bacteria (L. rhamnosus) into poly(vinyl alcohol) & sodium alginate-based nanofibers (VSPBe) and also the production of poly(vinyl alcohol) & sodium alginate-based nanofibers (VS) were successfully obtained. VSPBe and VS nanofibers were used to limit the Total Mesophilic Aerobic Bacteria (TMABc), Psychrophilic Bacteria (TPBc) and also Yeast and Mold count (TYMc) growth in the fish fillet. Dispersion stability potential -6.29 mV and -7.74 mV, for VS and VSPBe, respectively), thermal decomposition (a reduction in mass of VS and VSPBe at temperatures 50 degrees C, corresponding to < 5% and > 5%, respectively) and morphological properties of nanofibers (diameters between 60 nm and 580 nm) were revealed by characterization analysis. Microbiological tests demonstrated that VS and VSPBe were effectively delayed the TMABc and TPBc growth in fish fillets up to 38%. However, the antimicrobial effects of nanofibers were not pronounced for TYM growth in the fish fillet. The viability of probiotic bacteria could be provided after electrospinning process and the use of L. rhamnosus-loaded nanofibers for delaying microbial growth in the fish fillets could be evaluated as a natural/novel technique.