The number of hotels continues to grow, and competition among hotels will be more stringent. To that end, hotels in the city of Surabaya should develop a marketing mix if to survive or win the competition. As Kotler (2009) has stated, along with the increasing level of industry competition, marketing orientation began to shift to the concept of four Ps: price, place, product (or service), and promotion. Three hundred thirty-six customers were willing to answer a self-administered questionaire. These customers were grouped to travel agent guest, walk-in guest, and corporate guest. Four hypothesis were tested using multiple regression analysis. Results showed that price, place, service, and promotion simultaneously affect customer buying decision. Price is the most dominant factor influencing customer buying decision for travel and walk-in guest, while place on the other hand is the most dominant factor influencing customer buying decision for corporate guest. The recomendation was to give interesting pricing strategy for travel-agent and walk-in guest group by giving discount, special rate, and competitive price for revenue maximization during low season period. The recomendation for corporate guest group was to maintain and develop place strategy in d’SEASON hotel Surabaya, including the hotel maintaining and improving facilities and hotel accesibility. The factors such as price, place, promotion and service should be maintained because the marketing mix simultaneously affect the customer buying decision of all group