ENPatient-centered care is considered to be one of the essential pillars of a modern healthcare system. Thus, quality assessment based on patients’ perceptions, views and experiences in their journey through the healthcare system is recognized as one of the key principles for quality improvement initiatives. Measuring patient satisfaction can be confounded by expectations and prior experiences, which can be at least partly overcome by evaluating patient-perceived healthcare quality (PPHQ). Understanding the principal constituents of PPHQ may aid healthcare professionals and decision makers in the healthcare management process and help in creating instruments to meaningfully measure patient feedback. Herein, we aimed to analyze the primary determinants of PPHQ and their interactions, with a focus on patient experiences and healthcare accessibility, using the example of Lithuanian primary healthcare. For this purpose, we conducted a cross-sectional representative telephone survey that included a total of 1033 respondents (48% male) who had encountered primary healthcare during last 3 years. Survey questions consisted of sociodemographic characteristics, patient perceptions of healthcare service provision, patient experiences, self-reported health status and overall PPHQ ranked with a 5-point Likert scale as the primary outcome. The classification-regression tree (CRT) technique was used to analyze the relationship between different explanatory variables and PPHQ, as well as their relative importance and interactions.The majority of respondents (89%) evaluated PPHQ as acceptable or good. CRT analysis identified staff behavior, organizational accessibility and financial accessibility as the most important factors affecting PPHQ. Importantly, the latter factors surpassed the effect of other known PPHQ determinants, such as sociodemographic characteristics or health status. Further analysis has revealed that the relative importance of staff behavior, including understanding, attention and empathy, increased when more problems with organizational accessibility were encountered. In conclusion, our study suggests that PPHQ in primary healthcare may primarily be determined by organizational and financial accessibility and staff behavior, which may also act as an important mediating factor. Keywords: healthcare accessibility; healthcare quality; patient experiences; patient-perceived healthcare quality; primary healthcare. [From the publication]