Microplastic (<5 mm) ingestion has been recorded in Galeus melastomus, the blackmouth catshark, around the Balearic Islands. In total 125 individuals were analyzed for microplastic ingestion. Results have shown that 16.80% of the specimens had ingested a mean value of 0.34 ± 0.07 microplastics/individual. Stomach fullness index ranged from 0.86 to 38.89% and regression analyses showed that fuller stomachs contained more microplastics. A higher quantity of filament type microplastics were identified compared to granular or hard plastic type. No significant differences were given between ingestion values of two locations over the continental shelf providing further evidence of the ubiquitous distribution of microplastics. The findings in this study reflect the availability of this man made contaminant to marine species in seafloor habitats. Based on results from this study, data on microplastic ingestion could be used to study trends in the amount and composition of litter ingested by marine animals in accordance with descriptor 10 of the Marine Strategy Framework Directive. Display omitted •16.80% of the analyzed sharks ingest 0.34 ± 0.07 microplastics per individual.•G. melastomus with more replenished stomachs had higher quantities of microplastics.•Higher presence of microplastics filament in stomach contents of G. melastomus.•G. melastomus could be used as a common indicator species for microplastic ingestion. Galeus melastomus inhabiting the continental shelf off the western Mediterranean Sea ingest 0.34 ± 0.07 microplastics/individual.