BACKGROUND Periodic medical checkup helps improve life expectancy. Traders are a major economically active population in south eastern Nigeria and are expected to benefit from periodic medical checkup. A good knowledge and understanding of the prevailing health knowledge, attitude and preventive health behaviour of these traders is essential for creating population-specific health programs. OBJECTIVES To determine the knowledge, attitude and practice of periodic medical checkup by traders in South east Nigeria, as well as the influence of age, gender and educational status on its practice in this group. METHODS: A questionnaire- based descriptive study carried out among traders in Nnewi, South east Nigeria, who were selected randomly between September and October 2010. A total of 323 traders responded, 252 males (78.0%) and 71(22.0%)females. Themeanagewas 31.9± 10 years and the ages ranged from15 to 65 years withmajority(49.2%) between 20-29 years. Majority (61.0%) had secondary school education and 1.2% had post secondary school education. About 74.9% were aware of periodic medical checkup; all females and 67.9% of males. Major source of information was through friends (61.2%), then mass media(18.2%). The commonest known type of medical checkup was general examination (60.7%), then blood pressure measurement (55.4%). About 63.8% feel everybody needs medical checkup. Most (85.5%) feel medical checkups can improve their work efficiency. Only 29.4% of males and 39.4% of females practice periodic medical checkup. Age, gender and educational status were found not to affect practice of periodic medical checkup significantly. CONCLUSION: This study revealed a high level of awareness of periodic medical checkup, but a very low level of practice among this group. Effort should be made by health agencies to educate traders on the various types of medical check up, their indications and benefits as well as its practice encouraged.