This study contributes to the growing body of literature which suggests that training and supervision are effective methods of promoting appropriate drug use. While standard treatment guidelines and essential drugs lists are an important step, this research corroborates the proposition that these measures by themselves are insufficient to reduce inappropriate prescription practices. The study goes a step further than previous studies and begins to identify characteristics of effective supervision and training. Specifically, on-site supervision and regular supervision by doctors were more effective methods. Training prescribing personnel for at least six weeks and dispensing personnel for at least one week also correlated with more appropriate drug use. At least six weeks of training seemed particularly effective in influencing complex prescribing behaviour such as antibiotic prescription. Replication of this study in other environments would be necessary to confirm these findings.