The American Thoracic Society recommends that specific individuals who are classified as tuberculosis infected receive a year-long course of INH chemoprophylaxis. They further recommend that patients receiving medication be evaluated on a monthly basis to assess the individual for side effects related to the medication. The most prevalent side effects are hypersensitivity, GI distress, hepatitis and neurotoxicity. Subjective data relating to these side effects need to be elicited at every visit and a pertinent physical examination done. Careful monthly monitoring is required to evaluate the patient for the most prevalent and significant side effects of the medication. Nurses must be aware of the significance of this preventive measure, the adverse reactions which may occur with the drug therapy and the health teaching which contributes to patient compliance.