This study was conducted to systematically summarize trends in research concerning patients with coronavirus disease 2019 (COVID-19) as reported in Korean medical journals. We performed a literature search of KoreaMed from January 2020 to September 2022. We included only primary studies of patients with COVID-19. Two reviewers screened titles and abstracts, then performed full-text screening, both independently and in duplicate. We first identified the 5 journals with the greatest numbers of eligible publications, then extracted data pertaining to the general characteristics, study population attributes, and research features of papers published in these journals. Our analysis encompassed 142 primary studies. Of these, approximately 41.0% reported a funding source, while 3.5% disclosed a conflict of interest. In 2020, 42.9% of studies included fewer than 10 participants; however, by 2022, the proportion of studies with over 200 participants had increased to 40.6%. The most common design was the cohort study (48.6%), followed by case reports/series (35.2%). Only 3 randomized controlled trials were identified. Studies most frequently focused on prognosis (58.5%), followed by therapy/intervention (20.4%). Regarding the type of intervention/exposure, therapeutic clinical interventions comprised 26.1%, while studies of morbidity accounted for 13.4%. As for the outcomes measured, 50.7% of studies assessed symptoms/clinical status/improvement, and 14.1% evaluated mortality. Employing a systematic approach, we examined the characteristics of research involving patients with COVID-19 that was published in Korean medical journals from 2020 onward. Subsequent research should assess not only publication trends over a longer timeframe but also the quality of evidence provided.