Samples of organic cow's milk, conventional cow's milk, and cow's milk-based infant formulas were analysed for the occurrence of ochratoxin A by means of an HPLC method. The detection limit was 10 ng/l. Ochratoxin A was detected in 6 out of 40 conventional cow's milk samples (range 11-58 ng/l), and in 5 out of 47 organic milk samples (range 15-28 ng/l). No ochratoxin A was detected in any of the 20 infant formula samples. The ochratoxin A levels in cow's milk found in this investigation are sufficient to cause a higher intake of ochratoxin A than the suggested TDI of 5 ng/kg bw/day, e.g. in small children who consume large quantities of milk.