Lean techniques have yet to extend to the majority of manufacturers in developing countries where traditional work practices are dominant and cultural resistance to change is high.  This research consists of a case study about a Lean implementation at a clothing manufacturer in a developing country.  Production wastes are identified and appropriate lean techniques, namely Total Productive Maintenance, Kanban and Supermarket Pull, are used to eliminate or reduce them.  The potential impacts on the manufacturing system are first assessed using a system dynamics model.  The modeling results showed that system performance, in the form of reduced work-in-process, is improved by 34% on average starting immediately after the lean intervention, which was replicated by a similar trend in practice.  A similar improvement trend was achieved with the actual implementation of the selected lean techniques.  And since lean improvements are typically difficult to sustain over the long term, the system dynamics model is simulated over a 6 months period to ensure the achieved benefits are sustained.