The emission spectrum of HfCl has been investigated in the 3000 -18 500 cm Ϫ1 region at high resolution using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of HfCl 4 and helium. Two bands near 17 140 and 17 490 cm Ϫ1 were also measured in absorption using laser excitation spectroscopy. In this instance the molecules were created by laser ablation in a molecular beam apparatus. The observed bands have been classified into two electronic transitions, [7.6] 4 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 and [17.1] 2 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 involving a common lower state. A rotational analysis of the 0 -0 and 1-1 bands of [7.6] 4 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 and 0 -0, 1-1, and 1-0 bands of the [17.1] 2 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 transitions has been carried out and the equilibrium spectroscopic constants have been determined. The ground state principal molecular constants are B e ϭ 0.1097404(54) cm Ϫ1 , ␣ e ϭ 0.0004101(54) cm Ϫ1 , and r e ϭ 2.290532(57) Å. Ab initio calculations have been performed on HfCl and spectroscopic properties of the low-lying electronic states have been predicted. The ground state is predicted to be a regular 2 ⌬ state arising from the valence electron configuration, 1 2 2 2 3 2 1 4 1␦ 1 . On the basis of our ab initio calculations, we assign the observed transitions as [7.6] 4 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 and [17.1] 2 ⌬ 3/ 2 -X 2 ⌬ 3/ 2 .