Visual inspection showed 76% ascaridoid prevalence (>90% Anisakis) in herring viscera. 69% of Anisakis were found in the lower viscera (hind stomach and intestine). MRI can detect Anisakis accumulations in situ in the viscera of whole herring. MRI can detect anisakid larvae and their movements in fish muscle. MRI showed potential to investigate anisakids in a non-destructive-non-invasive way.