Experimental results are presented that demonstrate that the light intensity of a good-cavity single-mode standingwave dye laser can exhibit chaotic behavior. The governing attractor is of dimensionality 6.5 and entropy 50 kbits/sec. An examination of the pump-laser beam before and after its interaction with the dye indicates that the chaos is probably due to the turbulent flow of dye within the dye cell. This interpretation is confirmed by the absence of chaos in two similar dye lasers that use a dye jet rather than a dye cell. © 1987 Optical Society of America.