Background: Tuberculosis remains a disease of serious socio-economic and public health importance. The morbidity and mortality burden of tuberculosis in Nigeria and globally is great. Method: This is a non-randomized hospital based intervention study. Aim: To evaluate the impact of intensive patient education on antituberculosis drug treatment adherence in adult pulmonary tuberculosis (PTB) patients accessing treatment in Ebonyi State University Teaching Hospital, Abakaliki. Result: A total of 225 adult PTB patients who fulfilled the study inclusion criteria were recruited. Their ages ranged from 19 to 74 years with a mean of 37.4 12.7 years. The male: female ratio was 1.1:1. The control group comprised 117 adult PTB patients who accessed antituberculosis treatment from June 2004 to March 2006 while the intervention group comprised of 108 adult PTB patients who accessed antituberculosis treatment from April 2006 to October 2007. Data on their adherence to treatment were obtained from their TB treatment cards at the end of the intensive phase of antituberculosis drug treatment. Default rates of 10.2% and 34.2% were recorded for the intervention and control groups respectively. Majority of the defaulters resided outside Abakaliki (81.8%) in the intervention group and 80.0% in the control group while 18.2% and 20.0% of the defaulters resided in Abakaliki in the intervention and control groups respectively. There was a statistically significant difference in the default rates between the two populations of adult PTB patients. Conclusion: Intensive patient education has a potential to reduce non-adherence to antituberculosis drug treatment. Keywords : Adherence, default, education, intensive, resistance. Ebonyi Medical Journal Vol. 6 (2) 2007: pp. 76-82