In this study, we examined the effects of guardians` service quality perception(G-SQP) on patients` service quality perception(P-SQP) leading to patients` behavioral intention(P-BI) and the effects of G-SQP on guardians` behavioral intention(G-BI). To investigate the causalities of the variables, we collected national wide samples of 144 hospitals, 1456 patients and 1455 guardians of the patients and analyzed 1146 guardian-patient coupled cases refined with prerequisites such as missing value, outliers, normality and covariance conditions. Followed were contributions of the present study. First, G-SQP was a predictor of P-SQP. Second, in the first contribution statement, there was no statistically significant difference between inpatient and outpatient group. Third, proven was that G-SQP was a predictor of G-BI. Fourth, verified was that P-SQP was a predictor of P-BI. Fifth, G-SQP was a predictor of P-SQP being led to P-BI that meant P-SQP had a mediating role between G-SQP and P-BI. Since the guardians` perception affected patients` buying decision, the present study implied service managers of hospital settings should pay attention to guardians` perception of service quality as well as patients`. With such strategy, hospitals could improve financial performance in long-term.