Plastic carrier bags have gained popularity with Zimbabwean shoppers since they provide convenient carriage of groceries and related goods. However most of these have a short useful life and are often disposed into landfills or littered. This research was aimed at assessing the interaction between the High Density Polyethylene (HDPE) plastic carrier bag life cycle and the environment, hence identifying specific life cycle stages that pose significant threats to the environment. The study was conducted in accordance with the ISO 14040 based Life Cycle Assessment (LCA) methodology. The life cycle stages assessed include the extraction of HDPE, transportation of HDPE pellets, production of the bags, transportation of the finished goods to retailers and disposal scenarios. Improvement strategies were then identified to optimise the environmental performance of the plastic carrier bags.