Nine groups of subjects were trained to make a button‐press avoidance response and were then given different treatments before being tested for extinction. During treatment the experimental subjects were exposed to the light (CS) for 2, 5, or 10 sec on each of the ten trials. Subjects in the three response prevention groups (RP 20, 50, and 200) were physically prevented from making the avoidance response while subjects in the three flooding groups (Flooding 20, 50, and 200) were exposed to the CS irrespective of their responding. Subjects in the three Time Control groups (Time Control 20, 50, and 200) were given CS‐alone trials until they had been exposed to the CS for 20, 50, or 200 sec. Subjective fear was measured at different stages of the experiment by asking the subjects to report their fear on a 100‐point scale. It was found that RP was effective in producing extinction of avoidance at a total CS exposure of 20 sec whereas both the Flooding and Time Control procedures produced avoidance extinction at a total CS exposure of 200 sec. The Time Control groups showed greater resistance to extinction than their counterpart RP groups at each CS exposure. It was concluded that RP is the most effective procedure for the extinction of avoidance. Only the Time Control 200 group showed any evidence of fear extinction. None of the RP and Flooding groups showed a significant reduction in the strength of