The sensitivities of whole blood and clot cultures were compared in 155 patients with typhoid or paratyphoid fever. Salmonella typhi or S. paratyphi A were isolated from 98.7% of 5 ml 1:10 blood:broth ratio blood cultures and 94.8% of 5 ml streptokinase clot cultures (P greater than 0.05). There was no difference in the speed of isolation. Whole blood culture and clot culture were of nearly equal sensitivity in this group of patients.