['To evaluate the association between infant fussing and crying and developmental outcome in very low birth weight (VLBW) infants.', 'Hundred and seventeen VLBW infants were followed up to 24 months of corrected age. The duration of fussing and crying and frequency of fuss/cry bouts were measured at term 6 weeks and 5 months of corrected age. Cognitive and motor development was assessed at 24 months of corrected age.', 'The increased duration of combined fuss/cry at term associated with lower psychomotor developmental index (PDI), [regression coefficient (b)=-0.83, p=0.025]. Crying at term associated negatively with mental developmental index (MDI) (b=-0.91, p=0.040) and PDI (b=-1.10, p=0.015). The associations between fuss/cry and PDI, and crying and PDI persisted in multiple regression analysis (b=-0.89, p=0.030 and b=-1.23, p=0.018, respectively). Excessive fuss/cry (>or=180 min/day) at term associated with lower PDI (p=0.005) and at 6 weeks with lower MDI (p=0.024) and PDI (p=0.012). Increase in the frequency of fuss/cry bouts at 5 months associated with higher PDI in both simple (b=2.90, p=0.045) and in multiple regression analysis (b=3.60, p=0.019).'] Is crying behaviour in early infancy associated with developmental outcome at two years of age in very low birth weight infants?