In this study, an electrochemical determination of pirfenidone(PIR), an antifibrotic drug, was developed for the first time with a bare glassy carbon electrode(GCE) and a molecularly imprinted polymer(MIP)-based nanosensor. A molecularly imprinted polymer(MIP) incorporating o-phenylenediamine(o-PD), chitosan(CHIT), ionic liquid(IL), and diamond nanoparticles(DiaNPs) was utilized to modify a glassy carbon electrode(GCE), developing a stable and selective electrochemical nanosensor(MIP/CHIT@IL@DiaNPs/GCE) for PIR detection. The designed MIP/CHIT@IL@DiaNPs/GCE was characterized by electrochemical impedance spectroscopy(EIS), cyclic voltammetry(CV), scanning electron microscopy(SEM) and atomic force microscopy(AFM). The [Fe(CN)6]3−/4− redox couple was used as a probe to characterize the nanosensor by using voltammetric methods. Under optimum conditions, the bare GCE showed a linear response in the concentration range of 9.90 μM to 260.0 μM for the determination of PIR, and the detection limit was calculated to be 2.48 μM. While, the MIP/CHIT@IL@DiaNPs/GCE nanosensor exhibited good sensitivity with a linear range of 30.0 pM−1.0 nM and a detection limit of 9.29 pM. To demonstrate the applicability of the developed nanosensors to real samples, the determination was made from Pirfect® tablet and human serum.