The changes of land surface characteristics due to urbanization lead to various environmental problems such as increasing the runoff which can lead to flooding and the poor quality of receiving waters. Among different land uses in urban areas, the industrial areas are highly environmentally degraded land areas which annually discharge high amounts of contaminated stormwater to natural waterways. However, industrial areas plays major role in a country’s economy and therefore it is important to identify optimum strategies to improve the quality of runoff in such areas. Green Infrastructure (GI) practices integrate measures to restore the green space in urban areas and are currently becoming one of the promising strategies around the world as source control measures of stormwater, especially when implemented as treatment trains. For a complex land use like an industrial area, the reality in optimizing GI treatment trains can incorporate several aspects related to environmental, economic and social objectives which are expected of GI through their implementation. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was used in this study to identify compromise optimum treatment train configurations and the sizing combinations of GI treatment trains for a case study industrial area in Melbourne, Australia. Moreover, a sensitivity analysis was performed to validate the results obtained through TOPSIS by considering several weighting schemes for different performance measures. The results of the sensitivity analysis assessed the most sensitive performance measures for the weight changes. The methodology proposed in this study was successful in optimizing both the selection and sizing of a GI treatment train for an industrial area simultaneously.