The combined data from three fusion-evaporation reaction experiments have been utilized to investigate the semi-magic nucleus ${}_{28}^{58}{\mathrm{Ni}}_{30}$. To detect $\ensuremath{\gamma}$ rays in coincidence with evaporated particles, the Ge-detector array Gammasphere was used in conjunction with the charged-particle detectors Microball and LuWuSiA (the Lund Washington University Silicon Array), and a neutron detector array. The results yield a significantly extended level scheme of $^{58}\mathrm{Ni}$ comprising some 340 $\ensuremath{\gamma}$-ray transitions and include a total of at least 14 discrete particle decays into excited states of the daughter nuclei $^{54}\mathrm{Fe}$ and $^{57}\mathrm{Co}$. The level scheme is compared with large-scale shell-model calculations and cranked Nilsson-Strutinsky calculations.