The possible causes and consequences of changes to the coral reefs in different sites of Dahab, South Sinai, Egypt have been studied during the months October to December 2004. A total of 126 species of corals were identified, 107 of which were hard corals. No significant correlation was found between the number of divers (or snorklers) and each of diversity indices or percent dead corals. The percent cover of live corals was significantly lower at Laguna, compared to all the other sites and this is attributed to the effect of crown-of-thorns. Although the dive site of Mashraba is proximate to the flood zone, no impact due to excessive sedimentation or reduced salinity has been detected. Soft corals tended to increase with the flood distance and dead corals tended to decrease, but the correlation of both of them with the distance of the annual floods was not significant. Lighthouse is the most commonly used reef in Dahab as it is closer to most diving centers. Dahab is becoming more and more popular for tourism; number of divers per sites exceeds the diver carrying capacity (DCC). Construction of hotels, roads and beach cafes all pose potential threats. Damage is present and needs to be slowed down if we want to conserve these unique ecosystems for future generations. Coral reefs generate numerous benefits, defined as ecosystem services that has been also impacted and needs innovative government policies and effective monitoring to be restored.