Hitherto unexplored iodine-terminated germanium clusters GenIm +, n = 1–30, m = 0–49 have been formed by pulsed laser ablation of crystalline germanium tetraiodide in vacuum, and in situ analyzed by time-of-flight mass spectroscopy (TOF MS). The most abundant cluster found is Ge2I3 +. The structures of the clusters have been elucidated by extensive ab initio calculations at B3LYP/6-311G* theory level, as well as their infrared absorption intensity and Raman scattering activity spectra. A tendency to form preferentially chain-like clusters for n < 7, ring-like ones for n = 7–8, and compact Ge9 and Ge10 cores for n > 8 has been supposed from the cluster composition TOF MS data, and confirmed by the calculations.