This paper aims at analyzing the effects of quality announcement on performance of Egyptian listed companies. This has been conducted by event study methodology using announcements of international and national quality accreditation during the period from 2006 to 2012.

Abnormal Returns (ARs) are the differences between actual returns and estimated (normal) returns. It's argued that good informational content may lead to positive abnormal returns.

Results indicate that, hypotheses regarding the significance of differences between ARs with an estimation period of 30 days and a window from day -10 to day +10 could be accepted. Also, robustness check using CARs assures this significance. Findings show that informational content of competitive advantages has a positive effect on abnormal return of listed companies in the Egyptian exchange.