In Nigeria, SMEs contribute significantly to national output and play a vital role in regional economic development, particularly in semi-urban and rural areas such as Adamawa Central Senatorial District. The study adopted three objectives and three research questions concurrently thus: assess the level of adoption of business ethics practices among small and medium enterprises, examine the relationship between business ethics practices and the performance of small and medium enterprises and determine the effect of business ethics practices on the sustainability of small and medium enterprises in Adamawa Central Senatorial District. This study adopted a descriptive cross-sectional survey design using a quantitative research approach. The sample size of 200 was determined using Taro Yamane’s (1967) formula for finite populations. A multistage sampling technique was employed and data was collected using a structured questionnaire designed on a Likert scale. The collected data was then coded and analyzed using Statistical Package for the Social Sciences (SPSS). The study found out high ethical adoption among SMEs, strong positive relationship between ethics and performance and ethics significantly enhances sustainability. It was concluded that business ethics practices play a vital role in enhancing the sustainability and performance of SMEs in Adamawa Central Senatorial District. Hence, it recommended for institutionalization of ethical frameworks, capacity building and training of government agencies and business associations and strengthening regulatory support.