The present study aims to design a model for the role of social networks in environmental performance for sustainable development. This research seeks to identify the factors influencing environmental performance, with an emphasis on cultural factors. The study employs both qualitative and quantitative methods. In the qualitative phase, the Delphi method was used. To identify the relevant factors, the opinions of 20 experts and specialists in the field were gathered. Based on the interviews conducted, nine factors were identified. To validate these factors, quantitative methods were applied, and ultimately, four factors were selected as the final components to be included in the research model. In the quantitative phase, structural equation modeling with the partial least squares (PLS) approach was used to analyze the data through Smart PLS 3 software. The statistical population for this section consisted of small and medium-sized enterprises (SMEs) in Yazd Province. Standardized questionnaires were used for data collection. The content validity of the questionnaires was confirmed by experts, and their reliability was verified using Cronbach’s alpha coefficient. The results confirmed all the research hypotheses, showing that social networks have a positive effect on environmental performance. The positive impact of social networks on cultural and social capital, environmental awareness, and environmental responsibility was also confirmed. Moreover, cultural and social capital, environmental awareness, and environmental responsibility had a positive influence on environmental performance. Additionally, the mediating roles of cultural and social capital, environmental awareness, and environmental responsibility in the relationship between social networks and environmental performance were confirmed. The findings of the study indicated that cultural factors have a significant impact on improving the environmental performance of companies, emphasizing the need for greater attention to these factors to enhance performance and protect the environment. The results of this research can serve as a useful guide for policymakers and company managers aiming to improve corporate environmental performance.