Polystyrene (PS) submicron fibers of 14 wt% concentration were fabricated by electrospinning using dimethylformamide (DMF)-tetrahydrofuran (THF) solvent system. The surface morphology of PS fibers was modified from smooth to rough by changing the mixing ratio of DMF and THF in the spinning solution. The electrospun PS fibers with smooth and rough surfaces were then amidomethylated by treating with N-hydroxymethyl-2-chloroacetamide. PS fibers with higher roughness incorporated more amidomethyl functional groups on their surface, as confirmed by XPS analysis. This observation was further supported by BET adsorption isotherm results which showed a significant increase in specific surface area of rough PS electrospun fibers. Interestingly, amidomethylation has altered rough electrospun PS submicron fibers from extremely hydrophobic to hydrophilic. These chemically modified electrospun PS fibers with controllable surface roughness and wettability may be utilized as a carrier for proteins, mainly enzymes and antibodies, by covalent linkage through amino groups attached to their surface. © 2014 The Royal Society of Chemistry.