To understand the population dynamics of a species it is necessary to know age at first breeding and frequency of breeding by age class (Caughley 1977). Despite intensive studies of the Spotted Owl (Strix occidentalis) in Oregon, California and Washington during the last decade (Allen and Brewer 1985, Barrows 1981, Barrows and Barrows 1978, Forsman et al. 1984, Solis 1983), no one has been able to determine the age at which Spotted Owls become reproductively mature. In June 1984 we observed a 2-year-old female which bred successfully and, at the same time, a similar event was observed in California (Barrows 1985). This paper provides detailed documentation of successful nesting by a 2-year-old Spotted Owl in Oregon.