Consumers are paying close attention to green products to reduce the environmental impact on health issues. As the scope of this research, this current study focuses on determining consumers’ purchase decisions regarding green products using a survey conducted in a fast-growing developing country. This research was descriptive and considered a conceptual framework for extending the Theory of Planned Behavior (TPB), which was selected as the primary theoretical model. The significant contributions and main objectives of this study are as follows—to explore the present scenario of green marketing in Bangladesh with previous studies, and to fill a research gap regarding green purchase decisions by applying the TPB model with adding additional constructs, such as environmental concerns, green perceived quality, and future green estimates. A range of qualitative and quantitative techniques were adopted to collect data from the target groups, where a sample of young educated Bangladeshi consumers (n = 638) was used to consider the measurement and structural models by applying a partial least squares-structural equation modelling (PLS-SEM) method. The empirical findings show that consumers’ environmental concern (EC), green perceived benefits (GPB), green awareness of price (GAP), green willingness to purchase (GWP), and future estimation of green marketing (GFE) have a strong positive influence on consumer’ green purchase decision (GPD). Still, the green perceived quality (GPQ) has a negative influence on green purchase decisions (GPD). To inform consumers about green or eco-friendly products, this study provides valuable suggestions to companies, marketers, and policymakers for designing green marketing tools such as green advertising, green branding, and eco-labels. Based on these findings, it gives some managerial insights for the promotion of green products and green marketing.