In a prospective study of 300 young orthopaedic in-patients (less than 40 years) given spinal anaesthesia through a 22-gauge Whitacre (n = 150) or a 25-gauge Quincke spinal needle (n = 150), we found a 5.3% and a 9.3% incidence of post-spinal headache (PSH) respectively. Females (10.6%) had a higher overall incidence of post-spinal headache than males (5.6%) with more than twice as many females being affected in the 25 than in the 22-gauge group (14.5% vs 6.1%). The average duration of post-spinal headache was less in the 22-gauge group (36 h vs 42.4 h) as was the incidence of severe headache. It is concluded that the Whitacre 22-gauge needle is more suited for spinal analgesia in young female patients due to its ease of handling and its lower incidence of post-spinal headache.