Investigations on monkeys have shown that the application of the acidic dye Ponceau S red or the basic dye Alcian blue to the tongue surface facilitates identification of fungiform papillae and taste buds. Both of these dyes were now used in varying degrees of acidity on fixed and unfixed human cadaveric tongues in an attempt to determine the regional distribution of papillae and buds. Satisfactory staining was obtained with acidic Ponceau S red in 10% formalin and 10% trichloracetic acid (pH 2.5). For six tongues, the number of fungiform papillae ranged from 171 to 253 (mean 195) and these were located predominantly at the tip. Of the fungiform papillae, 67% had no staining of taste bud pores. The average number of visible taste pores on the other fungiform papillae was 3 (range 1-21). The correlation between the number of stained taste pores and underlying taste buds was confirmed using serial histological sections of 90 fungiform papillae. This work has shown that a mean of 193 taste buds are carried on fungiform papillae of the human tongue and that 87% of these are located in the anterior 2 cm.