Measurements of ground-state properties for nuclear structure studies by precision mass and laser spectroscopy Abstract. Atomic physics techniques like Penning-trap and storage-ring mass spectrometry as well as laser spectroscopy have provided sensitive high-precision tools for detailed studies of nuclear ground-state properties far from the valley of β-stability. Mass, moment and nuclear charge radius measurements in long isotopic and isotonic chains have allowed extraction of nuclear structure information such as halos, shell and subshell closures, the onset of deformation, and the coexistence of nuclear shapes at nearly degenerate energies. This review covers experimental precision techniques to study nuclear ground-state properties and some of the most recent results for nuclear structure studies.