Background: Digital banking and environmental sustainability are increasingly converging within banking strategy. In India, public sector banks (PSBs) are expanding paperless transactions, digital documentation, electronic payments and green-oriented financial practices. Objective: This study examines whether Green Digital Banking Practices (GDBP) are associated with customer satisfaction and identifies the role of digital service quality and perceived sustainability value. Methods: Primary data were collected through a structured five-point Likert questionnaire. Seventy-six responses were received; seven respondents who indicated that they did not currently use mobile or internet banking of an Indian PSB were excluded from inferential analysis, leaving 69 eligible digital-banking users. Data were analysed using descriptive statistics, Cronbach's alpha, Pearson correlation and hierarchical multiple regression. Results: GDBP showed a positive association with customer satisfaction (r = .363, p = .002). Digital service quality had a stronger positive relationship with satisfaction (r = .642, p < .001), while sustainability value was also positively related to satisfaction (r = .480, p < .001). In the final regression model, the three predictors explained 44.1% of the variance in satisfaction; digital service quality remained the only statistically significant unique predictor. Conclusion: Sustainable digital banking is positively connected with customer satisfaction, but the customer experience appears to depend particularly on reliable, responsive, secure and convenient digital service delivery. The findings suggest that PSBs should integrate environmental value into digital banking without allowing sustainability communication to substitute for core service quality.