The current study aims to identify the effect of viral marketing on the purchase decision of tourism and hotel services.  Viral marketing includes marketing tools represented in viral advertising campaigns, opinion leaders, "influencers", incentives, and electronic publishing media.  To achieve this goal, a questionnaire was designed and distributed to a random sample of customers in some five-star hotels in Sharm El-Sheikh. The total number of forms distributed was (900) with (30) forms inside each hotel, of which (688) were  (76.4%) is valid for statistical analysis.  The results of the field study concluded that most of the peoples opinions of the study sample agreed upon three elements of the viral marketing tools that affect them with regard to the decision to purchase the hotel tourism product represented in “incentives, electronic publishing means, and viral advertising campaigns".  The results also revealed the positive impact of viral advertising in terms of message content, mental image, an advertising medium, and stimuli combined in influencing the purchase decision.  The study recommended the adoption of viral marketing tools in tourism and hotel companies that may affect people's purchase decisions and employment by broadcasting the viral advertising campaign as being less costly and more successful.