Vaccination of goat kids against paratuberculosis provides protection against clinical disease, but the nature of the cellular reaction in lymphoid tissue has not been described. Fourteen of 28 male kids were vaccinated subcutaneously cranial to the scapula with a commercial paratuberculosis vaccine (Paratuberkulosevaksine, Central Veterinary laboratory, Oslo, Norway). After three weeks, seven of the vaccinated and seven of the control goat kids were euthanased. Tissues from the vaccination site and the draining prescapular lymph node were fixed in formalin or frozen. The remaining seven vaccinated goat kids received a subcutaneous injection of a pathogenic strain of M. avium subsp. paratuberculosis close to the vaccination site. Three weeks after the challenge, these seven goat kids and the remaining seven control animals were euthanased and the tissues were collected as for the previous groups. Blood samples were collected at various times throughout the experiment and humoral and cellular immune responses were detected in the blood 12 weeks after vaccination. Prescapular lymph nodes from all the goat kids were subjected to bacteriological examination. Histological examination showed that there was a granulomatous reaction at both the vaccination site and in the draining lymph node. ZN staining for acid fast bacilli and immunohistochemical examination for M. avium subsp. paratuberculosis showed reactivity at the vaccination site three weeks after vaccination but not at 12 weeks and bacteria were not detected in the draining lymph node at either time of examination. There was a significant follicular hypertrophy in the lymph node but significant changes in the proportion of area occupied by T-cell subpopulations in the diffuse lymphatic tissue of the lymph node cortex were not detected. The results of the present study suggest that large changes in T-cell subpopulations in the lymph node cortex does not characterise the successful immune response of goats vaccinated against M. avium subsp. paratuberculosis.