Aspergillus allhabadii MTCC 9988 isolated from pesticides sprayed cotton growing soil, were evaluated for decolorization of a textile dye, Reactive Black HFGR. The physiochemical parameters (shaking vs. static, pH, temperature, dye concentration and different carbon sources) were optimized and tested their effect on the degradation of textile dye in C-limited Czapek Dox media. Aspergillus allhabadii MTCC 9988 showed highest decolorization (90.57 ± 0.33%) of textile dye in shaking condition at temperature (30°C), pH (5.0), dye concentration (150 mg/L) and glucose as carbon source. Effect of different concentration of Reactive Black HFGR dyes ranging from 50 to 250 mg/L had a significant effect on decolorization (68.99 ± 0.67 to 90.57 ± 0.33%) with maximum decolorization at 150 mg/L and further increase in the concentration of dye showed a negative effect on the decolorization of the tested fungal strain. PrimeOA Publications International is one of the leading Open Access Publishers which is publishing 700+ peer-reviewed journals with the support of 50,000+ editorial board members as editorial team and aimed to disseminate the scholarly knowledge to the scientific society. PrimeOA Publications also organizing 3000+ International Scientific Conferences and events yearly all over the world with the support of 1000+ Scientific associations worldwide.