This paper first was focused on investigating the relative effect of each ISO 9001: 2000 certification factors on service quality and customer satisfaction in service industry. The empirical tests was conducted in service industry. The results are as follows. First, it shows that ISO 9001:2000 certification factors except requirements for quality management have a positive effect on service quality significantly. Second, it also indicates that service quality precedes customer satisfaction like other researches reported. Finally, different effects of ISO 9001:2000 certification factors on service quality are observed in the various industries.