Tellurium has attracted the attention of many researchers and manufacturers due to its unique properties. Through the current work, six fungal isolates have been screened for their ability to reduce potassium tellurite (K2TeO3) into elemental tellurium nanoparticles (TeNPs). The most promising fungal isolate was identified as Aspergillus welwitschiae and given the accession number (KY766958) based on molecular basis and has been used for biogenic (enzymatic) production of TeNPs. The produced TeNPs have been characterized using DLS, TEM and FTIR. Data showed that, the particle size is 60.80 d.nm with oval to spherical shape. The produced TeNPs have been evaluated for antimicrobial activity at 25 mg/ml. Data revealed antibacterial activity against E. coli and Staphylococcus aureus (MRSA). Evaluation of the effect of γ-irradiation on TeNPs production showed that, the productivity was improved at 1 kGy and suppressed gradually at higher doses.