Blood-phobic (n = 81) and injection-phobic (n = 59) patients fulfilling the DSM-III-R criteria for simple phobia were compared on a number of variables. There were no differences between the samples in age at onset, age at treatment, marital and occupational status, history of fainting in the phobic situation, and impairment. Higher proportions of blood-phobic subjects than of injection-phobic subjects reported having first-degree relatives with the same phobia (61% vs. 29%) and reported fearing that they were going to faint in the phobic situation (77% vs. 48%). In both samples, these proportions were higher in the subgroup with a history of fainting. Injection-phobic subjects rated 2 of 11 physiological items higher than did blood-phobics subjects, but the groups did not differ on behavioral variables. Overall, the similarities were more marked than the differences, and it is suggested that these two specific phobias should be regarded as one diagnostic entity.