Haloalkalitolerant fungi can grow at environments had high salt concentrations and pH values. The bioactive compounds produced under stressful conditions have potential biotechnological applications. In this study, 52 microfungi isolated from Acıgöl Lake/Turkey, offering polyextreme conditions, were screened for some biotechnological properties. The antimicrobial and antioxidant activities were determined using the agar diffusion and the DPPH radical scavenging method, respectively. Starch-iodine method, tributyrin plate assay, skim milk plate assay, carboxymethyl cellulose plate method were used for determining amylolytic, lipolytic, proteolytic and cellulolytic activity, respectively. Synthesis of silver nanoparticle was carried out using cell-free filtrate of microfungi. As a result, 40% of the isolates showed antimicrobial activity against at least one of the test microorganisms. Penicillium dipodomyicola showed the highest antibacterial activity against Gram positive and negative test bacteria, while P. brevicompactum showed the highest activity against Candida albicans. P. dipodomyicola and P. bilaiae were found to have free radical scavenging activity of a level (90% and above) that can compete with positive control. All of the isolates with amylase activity belonged to Aspergillus and Penicillium genera and the most prominent three of them were A. ochraceous, P. brevicompactum and A. flavus. While 55% of the isolates showed proteolytic activity, A. alliaceus had the highest activity. Almost all the isolates (92%) showed lipolytic activity. It was determined that especially the isolates of A. amstelodami, P. sizovae and P. solitum had a significant level of lipolytic activity. 35% of the isolates showed cellulolytic activity and in isolates of Cladosporium pseudocladosporioides, P. dipodomyicola and P. bilaiae were observed high activity. Eight of the isolates carried out AgNP synthesis within 24 h. When all the results were evaluated, it was determined that the isolates such as Aspergillus amstelodami, A. ochraceus, Penicillium dipodomyicola, and P. brevicompactum, have the potential to serve in different industrial areas.