The authors investigated the specific immunological competence of 31 patients with dermatophytosis using tricophytin antigen. Among them, 54.8% showed reaction to the delay phase (48 h) in the following proportions: tinea inguinale, 75%; tinea pedis, 61.5%; tinea unguium, 50% and tinea corporis, 20%. Other 62.5% showed positive result to the early phase (30 m). The association between these reactions revealed that, although the majority of cases with early positive reaction showed negativity to the delayed reaction, 20.8% presented positivity to both phases of the reaction. Out of the non-reactive patients to the delayed phase, 8 were submitted to the other cutaneous tests such as PPD, streptokinase, candidin, vaccinia and DNCB and showed preserved cellular immunity in 75%. These results suggest that, while using this reaction for immunological evaluation of patients with dermatophytosis, one should consider the overall immune status of the patient, the presence of early hypersensibility and the localization of the infection.