Faecal samples from 684 litters of suckling piglets from 100 indoor swine herds from all regions of Norway were examined for the presence of Cryptosporidium and Giardia, using sucrose gradient flotation concentration and immunofluorescent staining. Thirty-one (31%) herds and 57 (8.3%) litters tested positive for Cryptosporidium, while 10 (1.5%) litters in 10 different herds (10%) tested positive for Giardia. Molecular characterisation of nine Cryptosporidium isolates demonstrated both C. suis and Cryptosporidium sp. pig genotype II. There was significantly more diarrhoea among the Cryptosporidium positive piglets than among the Cryptosporidium negative piglets. Diarrhoea was not observed amongst litters in which Cryptosporidium sp. pig genotype II was found. There was a significant difference in the Cryptosporidium prevalence between litters from different geographical areas of Norway. This study demonstrates that both Cryptosporidium (C. suis and Cryptosporidium sp. pig genotype II) and Giardia infections are prevalent among suckling piglets in Norway.