Infection with L. intracellularis usually leads to subclinical inapparent infection in growing animals, but can significantly reduce animal efficiency. The study confirms the high prevalence of L. intracellularis in pigs aged from 11 to 28 weeks across the English pig industry. The identification of two risk factors (farmer-reported minor level Salmonella problems and boars brought onto farm), and two protective factors (farmer’s opinion on temperature as an important stress factor in his farm and pigs kept on more than two sites), highlights the importance of farm management practices on the prevalence of the infection within pig units. The results of this study provide veterinary professionals and pig producers with information that can be used to formulate suitable management strategies, and reduce the incidence of L. intracellularis exposure, improving animal welfare and profitability.