This prospective study was designed to assess the quality of skin analgesia provided by cryoanesthesia induced by a spray of freon (dichloro-tetrafluoro-ethane) for venous cannulation (22 or 24 Gauge cannulas). Eighty children between the ages of 5 and 15 years were allocated to two groups: 40 children had a conventional venepuncture, 40 others had a venepuncture under cryoanesthesia. The spray of freon was applied for ten seconds on the area of skin to be anaesthetised. The venous cannulation was carried out by an anaesthetist of the paediatric surgical unit. The intensity of pain at venepuncture was quantified with a visual analogic scale (range 0 to 100). The median values of the pain scores were 11.5 (0 to 50) in the cryoanesthesia group and 48 (11 to 75) in the control group respectively. It is concluded that freon spray provides a convenient analgesia for venepuncture in children aged 5-15 years.