A survey was conducted of mycobacterial infections in 1235 free-living deer from different regions of Scotland. Selected lymph nodes and spleen were pooled and examined by Ziehl-Neelson, culture and PCR. The overall prevalence of mycobacterial infection was 6.6%. Mycobacterium paratuberculosis was found in 2.1% and IS901+M. avium in 3.1%. No evidence of infection by M. bovis was forthcoming. The PCR procedure was the most sensitive technique, with a greatly reduced delay between sample preparation and result.