Diethylenetriamine (DETA) grafted polyacrylonitrile ((PAN) DETA-g-PAN) nanofibers (NFs) membrane was prepared by using electrospinning and chemical grafting techniques. Grafting of DETA to PAN was confirmed by Fourier Transform Infrared (FT-IR) spectroscopy. Adsorption kinetics of methylene blue (MB), rhodamine B (RB), and safranin T (ST) dyes onto PAN and DETA-g-PAN NFs membranes showed that adsorption leveled off at similar to 60 min. The kinetics data showed good fitting to pseudo second-order model. No change in the intra-particle diffusion pattern was observed for DETA-g-PAN membrane. The equilibrium adsorption data fitted well to Langmuir and Freundlich equations. The correlation coefficient (r(2)) varied from 0.940-0.995 for Langmuir and 0.941 to 0.999 for Freundlich equation. The maximum adsorption capacities (q(max)) of dyes increased in the order: MB (42.66 mg/g for PAN and 184.84 mg/g for DETA-g-PAN) < ST (72.46 mg/g for PAN and 195.7 mg/g for DETA-g-PAN) < RB (99.31 mg/g for PAN and 367.65 mg/g for DETA-g-PAN). These values are far higher than the values reported in literature.