There are no validation studies on patient satisfaction surveys in Spanish that can evaluate a hospital pharmacy drive-thru service. To develop and apply a pharmacy drive-thru satisfaction survey in Spanish during the COVID-19 pandemic with an analysis of the instrument validation. This was a qualitative study for developing, validating, and measuring patient satisfaction who used the drive-thru pharmacy during the COVID-19 pandemic. Content validity was obtained by a two-round Delphi and patient interview for apparent validity. The questionnaire was administered to 110 patients. The researchers made an item reduction by inter-item and item-total correlation analysis, stability validation by a test–retest, a test of reliability by Cronbach's alpha, and extraction of factors by an exploratory factorial analysis. Likewise, confirmatory factor analysis was developed to obtain a structural equation model based on generating an instrument of two sub-models of latent factors (service and place) with ten observed variables (items). A questionnaire was developed that relates six observable variables to the latent factor service and four observable variables to the latent factor place which are ten items based on a Likert scale from 1 to 5, obtaining a Cronbach's alpha = 0.901. The mean population satisfaction score was 4.523. The model presented a Root Mean Square Error of Approximation (RMSEA) of 0.026 (0.000–0.098), and standardized beta values greater than 0.2 according to the confirmatory factor analysis. Therefore, the goodness-of-fit of our model is consistent and the instrument of patient satisfaction with the use of drive-thru has been validated. Patient satisfaction had a mean of 4.9 points. This study developed and validated a reliable scale that evaluates satisfaction in a hospital pharmacy drive-thru service during COVID-19 pandemic that can be applied in other Spanish speaking countries. A great percentage of the patients that were evaluated had good satisfaction.