The tick responsible for Lyme disease is common in areas inhabited by deer. This should theoretically put military personnel at increased risk. A history of tick bite is uncommon and the characteristic skin rash often absent. Two examples of servicemen with neurological Lyme disease without cutaneous manifestations are discussed, and six other cases referred to the RAF Institute of Pathology and Tropical Medicine since 1987 briefly reviewed. Five of the cases contracted the disease in Germany and four were dependents. Lyme disease is under-recognised and under-reported, so that the scale of the problem cannot be determined. It is recommended that wooded areas inhabited by deer should not be frequented without adequate clothing, particularly in the early summer months when tick activity is at its greatest.