The Bushtit (Psaltriparus minimus) is evidently not a common host of the Brown-headed Cowbird (Molothrus ater). Only eight instances of cowbird parasitism on this species have been reported (Bent 1946, Friedmann 1963, Friedmann 1966, Friedmann et al. 1977, Smith and Atkins 1979, Friedmann and Kiff 1985). One involved the subspecies P. m. californicus, the other seven, P. m. minimus. Here we report the first known instance of cowbird parasitism on the subspecies P. m. plumbeus, the Lead-colored Bushtit, and an observation of adult Lead-colored Bushtits feeding a fledgling Brown-headed Cowbird.