The circular economy can contribute to the eco-efficient use of resources. Firms can obtain relevant benefits if they implement a circular economy. In Peru, the circular economy would create benefits, but it is not fully clear what factors explain the acceptance of firms of implementing a circular economy. Following the theory of planned behavior, the current research assesses the influence of attitudes, subjective norms, perceived behavioral norms, intentions, and pressures on behaviors towards the circular economy. A total of 71 medium-size firms based in Peru participated in an online survey. Six questions were focused on general information, and forty-seven questions evaluated the circular economy behavior of firms. A partial least square structural equation modeling technical analysis was used. It was found that attitudes (0.144), subjective norms (0.133), and perceived behavioral control (0.578) had a positive influence on intentions; also, perceived behavioral control (0.461) had a positive influence on behaviors towards the circular economy. Finally, pressures had a positive influence (0.162) on behaviors towards the circular economy. The model explained 64.3% of the behaviors towards the circular economy. The outcomes of the bootstrapping test were used to evaluate if the path coefficients are significant. This study showed that attitudes, subjective norms, perceived behavioral norms, intentions, and pressures explained circular economy behaviors. This information can help firms develop strategies to move forward a circular economy and provide governments information about the current situation of circular economy implementation to generate new norms and strategies for more implementation of circular economy measures in enterprises. The novelty is based on using the PLS-SEM technique.