Purpose: To study the prevalence of concurrent use of herbal and synthetic medicines among outpatients in a mission
hospital in Nigeria. Methods: A pre-tested questionnaire was used to collect data from a sample of 278 outpatient respondents in a mission
hospital. Results: One hundred and ninety three (69.4%) of the study population had used herbal and synthetic drugs concurrently within one-month of the study period. The top three conditions for which they were used were Malaria (88.5%), typhoid
fever (69.8%), cough and sore throat (60.1%) and asthma (19.1%) was the least. Concurrent use of herbal and synthetic drugs was significantly associated with age group (p< 0.001), gender (p = 0.026), monthly income (p < 0.001) and level of respondentís education (p < 0.001). Using multiple logistic regression models, the risk estimate of using of herbal drugs along side with synthetic drugs was higher among the middle aged (40- 59 years) group (OR: 2.4; 1.60 - 3.22). The risk was least common among age of = 60 years (OR: 0.16; 0.18-0.21) compared to youngest age group. The practice was higher among females (OR: 2.8; 2.2 -3.4) compared to males. The risk was most common among the middle income group
(OR: 4.2; 3.1-6.4) and it was increasing as the education level of the respondents increased. Conclusion: The prevalence of concurrent use of herbal and synthetic medicines in Nsukka is high. This could be the
reflection of what is happening in whole Nigeria. The risk of this practice is significantly associated with demographic and
socio-economic characteristics of respondents