Caudal epidural anaesthesia was performed in 25 awake or sedated infants, the sensory levels measured and the dose‐response determined (bupivacaine dose [ml kg−1] v. sensory level). The infants were divided into two groups based on body weight, group 1 (1.9–2.6 kg) and group 2 (3.4–7.0 kg). There was a significant difference between the dose‐response when comparing group 1 to group 2 (P<0.01). Smaller infants require a larger volume (ml kg−1) of local anaesthetic to achieve mid‐thoracic sensory levels than larger infants. In small infants, we recommend increasing the volume of local anaesthetic while still limiting the total bupivacaine dose to 3.25 mg kg−1by using 1.6 ml kg−1of bupivacaine 0.20% (3.20 mg kg−1) instead of 1.3 ml kg−1of bupivacaine