It is notorious that researches related to electrochemical sensors increased significantly due the promising characteristics that these devices present such as the possibility of obtaining information, with minimum manipulation of the studied system, in real time, and with low environmental impact. This article covers the carbon nanomaterials, presenting important aspects such as main properties, synthesis methods, and the application of these materials in the development of electrochemical sensors for the analysis of drugs and compounds of clinical interest. In this context, drug analysis is extremely important for quality control, to ensure that the medicine fulfills its role effectively without possible complications that could compromise the patient’s health and quality of life. In addition, analytical methods capable of determining compounds of clinical interest in biological fluids are extremely important for the indication of effective diagnoses. Thus, the versatility, selectivity, and portability of the electroanalytical techniques make the electrochemical sensors a favorite tool for the determination of drugs and compounds of clinical interest. It will be possible to follow in the present work that carbon nanomaterials have excellent thermal and electrical conductivity, strong adsorption capacity, high electrocatalytic effect, high biocompatibility, and high surface area. The possibility of formation of different composite materials based on carbonaceous nanomaterials that makes these materials promising for the development of analytical sensors, contributing to rapid, sensitive, and low-cost analyses can also be highlighted.