The application of new technologies, such as biotechnology, has its proponents and opponents. Public acceptance is an essential factor to develop biotechnology as a modern technology. The present study was conducted to assess the level of public perception and attitude toward the risks and advantages of genetically modified organisms (GMOs) in Shiraz, Iran. A questionnaire survey was conducted among people between the ages of 15 and 65 years old, with an average age of 33 years old. This study revealed that various education and expertise have the strongest impact on public attitude based on socio-demographic data. Approximately 75% of respondents had an optimistic attitude to GMOs. Based on the current study, many people (60%) have inadequate knowledge about GMOs, and correspondingly, the overall public attitude to these organisms in Shiraz is unstable. Moreover, most of the respondents were not familiar with biosafety regulations to control the claimed risks of GMOs. In summary, scientists, industries and agencies involved in GMO business should improve public trust and awareness to increase global acceptability of GMOs.