An immunopathological spectrum which correlates pathological forms with immune responses has been described in mycobacteriosis such as leprosy or tuberculosis. In paratuberculosis, a relationship between the response to immune based diagnostic tests and different types of lesions have been also previously reported. In this paper, the possible association between diagnostic tests and the histological lesions observed in sheep (focal or subclinical and diffuse or clinical) is studied. Cellular immunity was assessed by means of gamma-IFN and intradermal skin test and AGID and ELISA were used as serologic tests. A total of 134 sheep were evaluated by pathological methods and lesions classified as focal (located only in the lymphoid tissue), multifocal or diffuse. The latter were divided in two types according to the cellular types and the number of bacilli (borderline tuberculoid-borderline lepromatous). Focal lesions were usually negative to serology and positive to cellular tests. Among diffuse lesions, borderline-lepromatous type (with high amounts of bacilli) were positive to serology and negative to cellular tests whereas borderline-tuberculoid lesions gave the opposite reactions. Multifocal forms gave variable responses. The simultaneous use of cellular and humoral immunity based tests can detect the majority of infected animals. So, both groups of tests have to be regarded as complementary and their use should be considered in control eradication programs based on immunological diagnostic tests.