The position, energy and time sensitivity of the Timepix detector can be exploited for detection and spectroscopy of radioactive ions and their decay. The USB readout interface used for detector control and data acquisition can be adapted to receive an external clock and trigger from other detecting devices such as ionization chambers, scintillation and semiconductor detectors. Timepix can be thus used to (i) selectively detect chosen ions from a multiple-component ion beam, and (ii) record their subsequent decay. The high granularity of the pixel detector allows to apply not only temporal but also spatial coincidence technique for background suppression. This is particularly important for scarcely populated nuclei. Results are demonstrated by the measurement of 8He and 6He ions decay products and decay half-lives. Experiments were done on short-lived nuclei using radioactive ion beams of the Lohengrin fission fragment mass separator at the ILL Grenoble.