The co-morbidity of crying, feeding and sleeping problems at 5 months of age was investigated in a representative sample of 432 infants in South Germany. A crying, sleeping or feeding problem was reported in 32.7% of these infants by their parents and a further 14.6% had two or more of these problems. Little co-morbidity between crying and feeding problems was found. There were moderate to strong associations between crying and sleeping behaviours. Feeding problems showed little relationship to sleeping behaviour, but feeding type and frequency of feeds were related to night waking. Breastfed infants woke much more often at night. Crying and feeding problems at 5 months were poor predictors of sleeping behaviour at 20 or 56 months of age. Later sleeping behaviour was best predicted by infant sleeping behaviour. At 56 months, maternal distress due to sleeping and co-sleeping practices was predicted by maternal distress due to crying and feeding practices at 5 months of age. The predictions were significant but generally weak to modest in strength. Future studies on the consequences of crying or feeding problems should take into account patterns of co-morbidity. So-called ‘post-colicky’ sleep problems are not due to increased crying per se but rather appear to be the consequence of associated infant sleeping problems and parental caretaking patterns for dealing with night waking in infancy.