This study seeks to evaluate the environmental sustainability of significant construction projects, focusing on the Chabahar Port Development Plan and examining strategies employed to mitigate environmental impacts. The research has an applied purpose, quantitative characteristics, and employs a descriptive survey method for data collection. The study's statistical population consists of 260 employees involved in a large construction project at Chabahar Port. Utilizing a random sampling method based on the Krejci-Morgan table, a sample of 152 individuals was selected. The Bashiri Standard Questionnaire [1] served as the data collection instrument, with its validity and reliability substantiated by expert opinions and Cronbach's alpha, respectively. Data analysis was performed using SPSS software along with regression tests. The results indicated that all research hypotheses were supported. Consequently, measures for reducing energy consumption, conserving water, improving mobility and accessibility satisfaction, enhancing walking appeal, addressing noise pollution, mitigating traffic annoyance, reducing noise dissatisfaction, evaluating place quality, and analyzing air pollutants and their health impacts, as well as identifying environmental challenges, all contribute to the environmental sustainability of large construction projects at Chabahar Port. Finally, recommendations were proposed regarding the research title and its components.