This study explores how service quality in hospitals is perceived and measured among different groups of patients from four major continents (i.e. Asia, Europe, Australia and North America) who came to receive medical services in Thailand. Using stratified random sampling, data were collected from 2189 patients from 80 countries and four continents at six hospitals which provide healthcare services to international patients in Thailand. Four different models of measuring service quality based on different continents were developed with different numbers of quality dimensions and also a variation in the number of quality attributes. Asian patients provided a four-dimension model with 20 items; while a two-dimension model with 16 items was identified for European patients. Australian patients also revealed a two-dimension model but with 22 items, while patients from America provided a three-dimension model, also with 17 items. The study reveals that the development of service quality measurement models should not only consider context-specific items such as size and location, but should also include the nationality and demographic of the patient population. The findings also support that service quality has a significant impact on service satisfaction and the retention level of customers at the hospital. The concluded frameworks may guide healthcare providers to deliver better quality healthcare services and to sustain competitiveness.