The results of single exposure studies with exposure to trichloroethylene, TRI, (Monster et al., 1976), to 1,1,1-trichloroethane, MC, (Monster et al., 1979b) and to tetrachloroethylene, PERC, (Monster et al., 1979c) were used to study the precision in estimating the individual uptake from measured biological parameters after exposure. With simple linear and multiple linear regression analysis the individual uptake of TRI, MC and PERC was estimated from the concentrations of solvents and metabolites in biological media (blood, urine, exhaled air) at 2 h and at 20 h after exposure. The best results are obtained by estimation from the concentrations in blood, particularly of the solvents themselves. Including results of simultaneously measured concentrations in exhaled air or urine did not improve the estimate. © 1979 Springer-Verlag.