Endoparasites which are of importance for piglets are characterized by early infection and short incubation limes. Parasite infections with longer incubation times will only become apparent in a later life phase, although piglets can in principle become infected with all endoparasites. By contrast, typical piglet parasites are usually of little importance for older pigs due to the development of immunity. Isospora suis causes neonatal coccidiosis which is one of the most common diarrheal diseases in this age group and mostly occurs in the second week of life. Despite low mortality poor weight gain can lead to economic losses. Strongyloides ransomi is usually transmitted to newborn piglets via colostrum and can lead to heavy diarrhea. usually at around two weeks after birth. Heavy infections are frequently fatal. However due to the routine treatment of sows with avermectins, which are also effective against arrested larvae, this nematode has become rare. Infections with Ascaris suum frequently occur during the suckling period; however the long incubation period leads to a delay in the manifestation which is then seen during fattening. Only a very high worm burden with migrating larvae in the lungs leads to clinical symptoms like coughing. Thorough cleaning and disinfection using effective disinfectants, strategic application of anthelminthics in the sows, quarantine measures and the washing of sows before moving to the farrowing units can significantly reduce the infection pressure with endoparasites in general. On farms with a history of coccidiosis coccidiostats should be applied in the prepatent period to avoid the development of disease.