This report describes a case of the first isolation of Tenacibaculum maritimum from a captive-bred adult female sand tiger shark (Carcharias taurus) housed at the Cattolica Aquarium (Italy). The animal showed, between the second dorsal fin and the precaudal pit, skin lesions characterized by the presence of abundant whitish necrotic tissue. Through routine bacteriological examination, a bacterium was isolated from a skin lesion and subsequently identified as T. maritimum by phenotypic characters and species-specific polymerase chain reaction. The antimicrobial sensitivity of the isolated strain was evaluated for 11 antimicrobial agents by disk diffusion method. Antibiotic therapy was conducted with enrofloxacin at 10 mg kg⁻¹ i.m. on alternate days for 10 days. One month after the end of treatment skin lesions showed complete resolution and the shark recovered completely. The case presented here represents the first report of infection by T. maritimum in a sand tiger shark and highlights the potential pathogenic role of this microorganism in elasmobranchs kept in an aquarium.