This study extends research on the effects of institutionalization—by examining the trajectories of cognitive, language and motor development of 64 Portuguese infants and toddlers across the first six months of institutionalization, while determining whether pre-institutional adversities and the stability and consistency of institutional care predict children’s development. At time of enrollment, 23.4%, 32.8% and 31.3% of the children were moderately to severely delayed, respectively, in their cognitive, linguistic and motor functioning. Developmental problems persisted after six months of institutionalization. The accumulation of early pre-institutional adversities predicted cognitive and motor limitations at admission to the institutions, but not variation in subsequent development. The stability and consistency of institutional care also failed to predict developmental growth and change. Children who had never lived with their families of origin showed a better language development at enrollment than their counterparts who had lived with their families of origin before institutionalization. Such advantage was followed by a deceleration in language growth after six months of institutional placement. Results are discussed in terms of short- vs. longer-term effects of institutionalization.