Lung cancer is among the most life-threatening diseases, as it is by far the leading cause of death around the globe. However, plentiful studies have been reported with satisfactory results employing electrochemical biosensors, which make this method popular in lung cancer diagnosis. In assembling the sensing platforms, different materials of the sensor interfaces are utilized in electrode surface modification to enhance performance. A natural biopolymer chitosan (CS) is an outstanding material for the development of electrochemical biosensors. The unique physiochemical features exhibited by CS facilitate the preservation of its innovative traits and promote its secure adhesion onto the electrode surface. It also has inherent characteristics, such as high adsorption ability, good biocompatibility, eco-friendliness nature, greater heat stability, improved permeability, mechanical potency, outstanding layer-forming capability, and ease of availability. In combination with conductive materials, CS enables the modified electrodes to perform the best analytical results. This review is focused on the importance of CS in sensor configuration, advancements of CS-based electrochemical biosensors for detecting lung cancer biomarkers, and future prospects.