A multiple antibiotic resistant halophilic bacterium (VITP09) was isolated from the Head-Bunder Lake (Kumta coast, Karnataka, India). The bacterium was found to be Gram negative, motile, moderately halophilic and showed considerable growth in 3 to 5% of sodium chloride and can tolerate upto 21% of sodium chloride. Its 16S rRNA gene sequence indicated 99% identity to Halomonas hydrothermalis strain SMP3M. Among the different antimicrobial agents used, the halophilic bacterium was found to be resistant to ampicillin (1.02 mg/ml for MIC90), methicillin and vancomycin. β-lactamase assay in the presence of sulbactam confirmed the involvement of class-A β-lactamase in Halomonas hydrothermalis VITP09 resistance. Presence of sodium chloride (1 to 11%) in the growth medium does not affect the production of β-lactamase. Analysis of the enzymatic parameters revealed a Km of 88.33 μM, which is comparable to the β-lactamase reported for the enzyme isolated from the clinical isolates. The presence of such β-lactamase mediated antibiotic resistance in halophilic organisms could be a potential environmental concern and the emergence of such resistant halophiles and the spread of antibiotic resistance among halophiles, is danger for organisms of aquatic, terrestrials and human health.