Every company will face tight competition with other companies. One of the best efforts to keep and get customers is by managing service quality, product quallity and word of mouth. The objectives of this research is to analyze how far the influence of service quality and product quality on interest to choose (WOM) tourist bus PO. Nugroho Semarang. The object in this research is passengers of tourist bus PO. Nugroho. The analysis tools is the reliability test, validity test, regression analysis, F test, t test, and the coefficient of determination. sample in this research amounted 100 respondents used purposive technique sampling. The data collection is obtained by distributing questionnaire to the passengers. The result showes that independent variable of service quality (X1) and product quality (X2) have significant influence towards the interest to refer (WOM) with regression coefficient (β) is 0,555 (X1) and 0,404 (X2) and significance level of 0,000 (X1) and 0,001 (X2). Based on the results of this research, PO. Nugroho Semarang should be improve the service quality especially in assurance to secure the goods when the passengers get off from the bus.