Electrochemical sensors based on carbon nanotubes are widely used in biomedical studies. According to design the sensors can be divided into three groups: (i) sensors based on a carbon nanotube array; (ii) sensors manufactured by means of composites containing carbon nanotubes; (iii) sensors, which are electrodes with working surface containing carbon nanotubes. The development directions of sensors of the first and the second group, and also sensors of the third group which are manufactured by abrasive immobilization of carbon nanotubes on an electrode surface and by solvent dispersion and casting immobilization of carbon nanotubes on an electrode surface by means of N,N-dimethylformamide, surfactants, and Nafion are analyzed. The general information on manufacturing techniques of these sensors is given. The opportunities of these sensors for biomedical researches are demonstrated.