The aim of the present study was to investigate the ability of intensively reared European wels, (Silurus glanis L.) to adapt fish to pond conditions. Studies were carried out in two ponds in 1992 and four in 1993. The wels were stocked into the ponds when they were about 11 months of age and had average weights of: 498 and 469 g (1992) or 138, 281, 394 and 213 g (1993) respectively. When they were harvested at the age of 15-20 months, the average weights had increased to 1.461 and 2.125 g (survival 97 to 100%) for the fish stocked in 1992, and to 659, 1.323, 2.057 and 1.382 g (survival 86, 100, 87 and l00%) for the 1993 stock. Thus, European wels cultured intensively under controlled conditions do not lose their ability to actively seek and feed on live prey. Consequently it appears that intensively cultivated European wels may be stocked into ponds, and intensive rearing enables the stocking of fish at one year of age when the body weight may approach 500 g.