To test the capacity of the cholera-infected human intestine for active transport of sugar and amino acids, the ability of jejunal mucosal cells from patients with cholera to concentrate several substrates was measured quantitatively. Biopsies of jejunal mucosa were obtained during and after acute diarrhea of cholera, and the mucosal cell uptake of α-methylglucoside, l-Iysine, and l-leucine was measured in vitro. There was no difference between control and diseased tissues in the ability to concentrate these substrates. It is concluded that the mechanisms of cellular accumulation for glucose, and for neutral and acidic amino acids are not significantly affected by cholera. Furthermore, in spite of the sprue-like morphology found in a majority of jejunal tissues studied, concentrations of substrates were similar to those reported from normal occidental volunteers.