Up to now, oxaliplatin hypersensitivity diagnosis relies upon an evocative clinical history and a confirmation by skin tests, especially intradermal tests. We report here a case of anaphylactic reaction to oxaliplatin. Besides the usual in vivo tests, we applied the basophil activation test (BAT) to confirm the diagnosis. Concordance between BAT and skin tests results suggests the usefulness of the in vitro test as diagnostic tool in drugs hypersensitivity. Further studies will be required to standardize BAT in this indication.