Background: Satisfaction is one of the meaningful indicators of patient experience of health care Services. Asking patients what they think about the care and treatment they have received is an important step towards improving the quality of care, and to ensuring that local health services are meeting patients’ needs. Methods: Institutional based cross sectional study was conducted from September to October 2013 in Mettu Rural district, Ilubabor Zone, Oromia region, Southwest Ethiopia. A total of 390 subjects were involved in the study. Data was collected using structured questionnaire and analyzed by SPSS for windows version 16.0.Statistical test to analyze the data. Results: The questionnaire was administered to a total of 396 patients with 98.5% response rate. Out of the participants, 47.9% were male and 31.8% of respondents were in the age group of 35-44 years old, 31.8% of clients were unable to read and write and 71.3% were occupationally farmers. The finding of the study showed that the overall level of client satisfaction level with the OPD rendered at four growing health centers was 57.9%. Satisfaction was reported to be highest for amenities variable (71.3%) and lowest for provider characteristics (63%) related to courtesy and respect for respondents. Furthermore, satisfaction with the health care rendered at OPD was found to have significant association with accessing prescribed drugs and patients’ waiting time. Conclusions: This study showed that clients’ satisfaction level lower in the study health centers when compared to other similar studies in the country. Lack of drugs and supplies, poor information provision, long waiting time, poor cleanliness, lack of privacy, lack of necessary equipment and lack of water and electricity were found to be major causes of dissatisfaction. Therefore, the concerned body district Health Office, all the Health Center staffs should consider these service areas in order to improve customer satisfaction.