This paper presents a novel approach based on the Appraisal Theory to analyze user-generated, open-ended online restaurant reviews. We selected reviews (N=1100) from restaurants of two Portuguese touristic regions and focus, through content analysis, on the recognition of the main aspects, sentiments and types of attitude mentioned in such reviews. We also measure the interrater agreement on the recognition of the types of attitude. The main findings show that Quality of Food, Staff and Communication, Price and Atmosphere are the most frequent aspects mentioned in the reviews. Positive appreciation is the attitude expressed in most of the sentences. Most of the reviews present a positive evaluation of the restaurants. The interrater agreement among raters on the recognition of the types of attitude ranges from 0.82 to 0.92. Results reveal the main aspects that restaurateurs should take into account to make decisions in order to improve the business as a whole.