This study explores the factors influencing shrimp farmers’ adoption of Good Aquaculture Practices (GAPs) in traditionally managed aquaculture ponds cluster in Pinrang Regency, South Sulawesi Province, Indonesia. The factors influencing shrimp farmers’ decision to apply GAPs to traditional ponds in Pinrang Regency were analyzed using the Theory of Planned Behavior (TPB) with structural equation modeling (SEM). The analysis results showed that shrimp farmers’ willingness to adopt GAPs was strongly influenced by their attitude that GAPs can increase their production or income, improve a positive reputation in society, and contribute to improving the aquaculture environment. Meanwhile, the main impetus for adopting GAPs came from exporters or local entrepreneurs and directives and assistance from the relevant government, universities, and academics. The shrimp farmers believe that to maximize the level of application and the adoption of GAPs, improving pond engineering and managing environmental limiting factors are of high priority. The decline in aquaculture pond water quality is closely related to the condition of ponds with problems exchanging water, particularly disposing of aquaculture waste after the operation.