We report the realization of two-dimensional electron systems in InSb quantum wells. AlxIn1-xSb barriers were selectively delta-doped with Si to produce electron densities between 0.9 x 10(11) and 4 x 10(11) cm(-2) with electron mobilities as high as 97 000 cm(2)/V s at 4.2 K. A decrease in the electron density and an increase in the electron mobility are observed when the distance between the quantum well and the dopants is increased.