ZSM-5 (Seolite Sconoy Mobil) aluminosilicate zeolites synthesized by the hydrothermal method were incorporated into the hydrophobic ethyl cellulose (EC) nanofibrous membrane. The performance of synthesized nanofibers was investigated for a gravity driven oil–water separation. The synthesized ZSM-5 nanozeolites and EC/ZSM-5 composite nanofibers were characterized using XRD, FESEM, XPS, FTIR and AFM analysis. The permeability of EC/ZSM-5 5 wt% for oil in water mixture was in order of n-hexane (5170 ± 60 L/m2 h) > n-heptane (4600 ± 50 L/m2 h) > cyclohexane (4350 ± 35 L/m2 h) > pump oil (3780 ± 28 L/m2 h) > lubricating oil (3200 ± 25 L/m2 h) > motor oil (2980 ± 20 L/m2 h) with a separation efficiency higher than 99.90% for the studied oil/water mixtures separation. The potential of nanofibers toward oil absorption from oil/water mixtures was also investigated for 7 cycles of absorption process. The absorption capacity was found to be 525.6, 423.4 and 198.3 g/g for motor oil, cyclohexane and n-heptane using EC/ZSM-5 nanofibers. The obtained results revealed that ZSM-5 loaded-EC nanofibrous membranes can be used as efficient membranes for oil/water separation.