Actinomycetes such as Streptomyces sp serve as a good source of L-asparaginase, a pharmacologically important enzyme for the treatment of many ailments. In this study, a mangrove associated actinobacterium, Streptomyces gilvifuscus MKA19 was screened for L-asparaginase production, and the produced enzyme was purified. The purified enzyme exhibited the specific activity of 4.70 IU/mg with 1.68-fold purification and the yield of 50.72%, with a molecular weight of 85 kDa. The antagonistic activity of the enzyme against human pathogens was evaluated by agar well diffusion method, anticancer activity of the enzyme against various cancer cell lines was evaluated by MTT assay and the invitro antioxidant activities (DPPH, hydroxyl radical scavenging and nitric oxide scavenging assays) of the enzyme were also evaluated. The results on the antagonistic activity of L- asparaginase against human pathogens exhibited the maximum zone of inhibition (25 mm) against Streptococcus mutans and S. pneumoniae at 40 µl concentration. The enzyme possessed significant inhibitory effect against MCF-7 cell line with the IC50 value of 105.681 µg/ml. The total phenolic content (GAE) of L-asparaginase was found to be 0.0352 mg/ml. The antioxidant properties of the enzyme by DPPH scavenging, Hydroxyl radical scavenging and Nitric oxide scavenging assays exhibited the IC50 value of 33.66, 271.67 and 221.31 µg/ml, respectively. From this study, it could be confirmed that the actinobacterium, S. gilvifuscus effectively produced the enzyme L-asparaginase with pharmaceutical potential.