Background: Appropriate patients' perceptions as one of Patient Reported Outcome Measures (PROMs), are shown to be critical for the sustainable success of implant therapy, little is known however of how they prospectively evolve throughout the treatment process.Objective: This study aimed to prospectively assess patients' perceptions before and after treatment with dental implants and to identify the impact of patients' characteristics on their perceptions.Materials and methods: Patients' perceptions on implant therapy were prospectively assessed by means of purpose-made questionnaire, rating the extent of agreement/ disagreement with a set of statements on a visual analog scale. The questionnaire was collected before initial consultation with the implant dentist and post-treatment at least 1 month after prosthetic loading of the implant. Changes in patients' perceptions were analyzed with the Wilcoxon signed-rank test.Results: Pretreatment questionnaire was collected from 359 patients. While 245 of them proceeded with implant therapy, 145 received final restoration within the timeframe of the study and completed the post-treatment questionnaires between 1 and 6 months after prosthesis delivery. The most common source of information was dental professions (72.4%). Although patients' perceptions were more realistic at post-treatment, few improper perceptions persisted as only 51% of patients agreed with the statement "There is a chance of dental implant failure," 28% agreed with the statement "Dental implants last longer than natural teeth," and higher percentage of patients agreed with "Dental implant therapy is appropriate for all patients." Conclusions: Although patients appear to harbor more realistic perceptions of implant therapy, certain improper perceptions still persist at post-treatment. The design of appropriate patient educational program might be essential to correct misperceptions that might affect long term success of implant therapy.This study had been registered on Thai Clinical Trials Registry (TCTR) with the TCTR identification number: TCTR20181101001.