Under spinal anesthesia, different types of nerve fibers forming spinal nerve roots are unequally blocked. Objective: to estimate differences in the development of temperature, sensory, and motor blockades when performing different procedures of spinal anesthesia. This prospective study covered 70 patients undergoing different operations. In accordance with the procedure of spinal anesthesia, the patients were divided into classical (n = 35) and unilateral spinal anesthesia (n = 35) groups. The performed study has indicated that blockade of temperature fibers occurs, and first, next is that of sensory neurons, and at last motor ones. The latent period of temperature blockade is about 1 min and that is an early predictor of evolving sensory block. At all stages and under traditional and unilateral spinal anesthesias, the width of temperature blockade was 1–2 segments higher than that of sensory blockade. The lower bupivacaine dosage used with the unilateral procedure gave rise to even greater block differentiation. Sensory anesthesia developed more slowly, but motor blockage did fully in not all cases.