The place and time of birth influence the mortality of premature infants. We studied the effect of prematurity, time of birth, birth hospital level and district on the development and behaviour in a national cohort of 5-year-old Finnish very low birthweight infants (VLBWI). All surviving VLBWI (gestational age <32 weeks or birthweight <or=1,500 g) born in 2001-2002 in level II or III hospitals in Finland and full-term controls were included. The parents of 588 (64%) VLBWI and 176 (46%) controls returned the Five to Fifteen questionnaire (FTF) on the development and behaviour of their 5-year-old children. The questionnaire scores were linked to data from the National Medical Birth Register, the Hospital Discharge Register, the Register of Congenital Malformations and the Cause of Death Register. VLBWI had lower developmental and behavioural scores compared to the controls in all FTF domains. In VLBWI, the scores were less optimal, the lower the gestational age was. The time of birth, birth hospital level and district were not associated with the developmental and behavioural scores in VLBWI. In conclusion, short duration of pregnancy adversely influences development and behaviour in VLBWI. Despite differences previously demonstrated in mortality related to time and place of birth, there were no differences in developmental and behavioural scores in VLBWI according to the time of birth, birth hospital level or district. Thus, the survival advantage in level III hospitals seems not to be gained at the expense of behavioural or developmental problems.