Self-giant-pulsed operation of ruby lasers at 77 and 300°K and Nd 3+:YAG lasers at 77°K pumped by the 5145-R output of a pulsed argon ion laser is described. Self-giant-pulsed operation was obtained by: (1) static mirror misalignment, and (2) static misalignment of the fila-ment of the pumped laser material with respect to the mirror resonator axis. An output that consisted of a single "giant" pulse could be obtained for ruby by either method; for Nd3+:YAG, the output always consisted of one or more "giant" pulses and characteristic relaxation oscillations. These results are compared with the predictions of the theoretical model of E. R. Peressini in which the self-giant pulsing of these lasers is described as a limiting case of spiking. The relaxation oscillations in the output of ruby lasers are compared with the theoretical predictions.