Nanofiber systems with various composition and biological properties have been extensively studied for various biomedical applications. The electrospinning process has been regarded as one of the versatile techniques to prepare nano to microfibers. The electrospun nanofibers are being used especially in textile industries, sensors, filters, protective clothing, energy storage materials, and biomedical applications. In the last decade, electrospun nanofibers have been highly investigated for drug delivery systems to achieve a therapeutic effect in specifically targeted sites. Various drugs or biomolecules can be easily loaded into the electrospun nanofibers by direct or indirect methods. The proper selection of polymers (or blends of various polymers), drugs, solvents to prepare the composite nanofibers with desired morphology are the tools in enhancing the bioavailability, stability, and bioactivity of drugs.