Telemedicine has been an emerging method for delivering healthcare services due to the challenges brought by the COVID-19 pandemic. This descriptive quantitative correlational study is aimed at assessing the knowledge, attitudes and perceptions (KAP), and their relationship among adults aged 18-34 without prior experience in the use of telemedicine in Manila, Philippines during the COVID-19 pandemic. The study had 322 eligible respondents who answered an online survey questionnaire of three parts that asked for their socio-demographic profile, KAP on telemedicine. Descriptive statistics, profile analysis and Spearman's rho were utilized as statistical tools. The respondents' knowledge was on an average to low level, and attitude and perception towards telemedicine were both neutral. Results showed no significant difference between the KAP of the respondents when analyzed according to socio-demographic variables. Knowledge and attitude have a weak positive linear relationship while knowledge and perception have a moderate positive linear relationship. A strong positive linear relationship was indicated between attitude and perception. A positive attitude can be attributed to a positive perception towards telemedicine but both do not consequently come from high knowledge levels of it.