The aim of this study is to examine the impact of product variety and product complexity on firm's operational performance when they are operating in a globally connected green supply chain. A survey utilizing a self-administered structured questionnaire was used to collect data from 161 frontend merchandisers of apparel manufacturing firms in Sri Lanka. The results indicate that the relationship between product variety and operational performance is fully mediated by green supply chain management while the relationship between product complexity and operational performance is partially mediated by green supply chain management. Thus, organisations that operate dynamic product portfolios (i.e., a variety of complex products) need green supply chain management practices to improve operational performance. This study emphasises the complementary application of the resource based view with coordination theory to explain how resources of the firm should be allocated and coordinated with regard to variety and complexity.