This study examined the relative effects of weekly and daily group feedback on the customer service behaviors in a gas station. Participants were four employees providing full services to the customers. Four target service behaviors, which were identified from the job description for the employees, served as the dependent variables. The data were collected by a supervisor. The independent variable was the frequency of group feedback on the four service behaviors: weekly and daily group feedback. An ABC within group design was adopted. After baseline (A), the weekly group feedback condition (B) was introduced. In the next phase, the daily group feedback condition (C) was introduced. Both weekly and daily group feedback were presented in a graph form and posted at a conspicuous location. Results showed that both weekly feedback and daily feedback conditions were effective in increasing the target behaviors. And, there was difference in the effects between the two conditions.