Wheezing in infancy has been associated with subsequent asthma, but whether cough similarly influences asthma risk has been little studied. We sought to determine whether prolonged cough and cough without cold in the first year of life are associated with childhood asthma. Prolonged cough in infancy and cough without cold are associated with childhood asthma, independent of infant wheeze. These findings suggest that characteristics of cough in infancy are early markers of asthma susceptibility, particularly among children with maternal asthma.