Poly(3-hydroxybutyrate) [P(3HB)] nonwovens were obtained from polymers enriched with nucleants using the melt-blown technique. The most important physico-mechanical parameters, susceptibility to hydrolytic degradation (in neutral and alkaline medium) and to biodegradation, were analysed for the obtained nonwovens. It was determined that P(3HB) nonwovens, compared to popular polypropylene (PP) nonwovens, are characterized by elementary fibres with several times greater average diameter, greater mass per unit area and greater air permeability value. P(3HB) nonwovens are, on average, seven times more susceptible to breakage, and their elongation at maximum force is more than 50 times smaller than that for PP nonwovens. Hydrolysis of P(3HB) nonwovens is faster in an alkaline than in a neutral medium, and the observed relationships led to the conclusion that, at the start, short chains are subject to hydrolysis. Analysis of the weight loss associated with the degradation in bioreactors showed that P(3HB) nonwovens are more susceptible to biodegradation under anaerobic than under aerobic conditions.