Low water systems have become important for organic synthetic reactions catalysed by enzymes. Esterification reactions could be catalysed by lipase in multiphasic reaction media, such as foams, containing excess water. The esterification of glycerol with oleic acid catalysed by lipase in aqueous foams has been characterised. More than 80% of the oleic acid was converted to glycerides within 10 h. Preliminary characterisation of the reaction with respect to time, pH and temperature indicate that acylglycerol synthesis in foam media as similar to hydrolysis by the same lipase. The observed high K-m of glycerol for the esterification reaction may be due to poor surface active properties of glycerol. The unique advantages of foam as a medium to conduct lipase reactions are discussed.