Behavioral parent training (BPT) is one of the most commonly utilized research treatments for young children with externalizing behaviors. Most BPT research, however, has been conducted with mothers. Thus, insufficient data exist as to the benefits of father participation in BPT. This paper provides rationales for why fathers should be included in BPT and an extension of previous critiques on father participation in BPT to critically evaluate recent research (1989-2003) in the same area. Several limitations of this body of research make it difficult to draw conclusions about the benefit of including fathers in BPT. Future research should be conducted with methodologically-sound designs to examine treatment outcome with fathers.