We review and synthesize empirical evidence at the intersection of two populations: children with language learning impairment (LLI) and children from immigrant families who learn a single language from birth and a second language beginning in early childhood. LLI is a high incidence disorder that, in recent years, has been referred to by researchers and clinical educators as specific language impairment (SLI), primary language impairment (PLI), developmental language disorder or language disorder not otherwise specified. Over the past two decades, significant international attention has been directed at the LLI-sequential bilingual learner interface. Researchers have developed linguistic profiles of children with LLI who are learning different language pairs, investigated the diagnostic accuracy of various measures and, more recently, examined the relative efficacy of different treatment protocols. Participants in these studies range in age from 3 to 12 years. A main goal of this review is to relate available evidence to key theoretical and pedagogical issues. An additional aim is to indicate main areas of need for future research.