SUMMARY Enniatins were determined in the mycelium of Fusarium sambucinum grown in liquid surface culture on semidefined or undefined media. Light was required for significant enniatin production, which was also favoured by moderate growth temperature. Production was supported by various carbon and nitrogen sources. Growth on a medium containing (w/v) 5 % lactose and 0·8 % tryptone, at 20 °C, with daily 12 h photoperiods, yielded 1·7 g enniatins/1 (10 % of mycelial dry wt). Glucose inhibited sporulation of F. sambucinum.