There is evidence that children with asthma exhibit more externalizing behaviour problems than other children. Impulsive behaviours can mark the onset and severity of externalizing behaviour problems. The present paper reports an exploratory examination of relationships between functional asthma severity and impulsivity in 6 and 7 year old children with asthma (N = 16). Participants with varying functional asthma severity were recruited at age 5 from a larger community study (the Children’s Learning Study). Parents completed items from three subscales of the Connors’ Parent Rating Scale-Revised (CPRS-R), the Hyperactive-Impulsive, Conners’ Global Index: Restless-Impulsive and the DSM-IV Hyperactive-Impulsive subscales. Children completed the Two Choice Paradigm (TCP), a computer program measuring delay aversion type impulsive behaviours. Mean (SD) CPRS-R Hyperactive-Impulsive, Conners’ Global Index: Restless-Impulsive and DSM-IV Hyperactive-Impulsive subscale scores were 59 (11), 56 (10) and 59 (10) respectively. There was no correlation between functional asthma severity and delay aversion or CPRS-R subscale scores and there was no evidence of a trend for such a relationship. Preliminary investigations conducted with a small sample of 6-7 year-old children with asthma thus suggest that functional asthma severity is not related to impulsivity.