Vegetables are an important source for the essential vitamins and minerals that are necessary for optimal health. This research investigated changes in vegetable intake over time in the Korean population from 1998 to 2017, focusing on preparation methods of vegetables and location of consumption. This cross-sectional study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) that was established in 1998 to assess the health and nutritional status of the South Korean population. This research utilised information from 1998 to 2017 which is the extent of all available KNHANES data. Vegetable consumption was grouped, according to preparation methods and common eating locations. Both crude and age-standardised means of vegetable intake were derived via a 24-h dietary recall. All participants who completed a 24-h dietary recall survey were selected for the analyses. This included 109 220 individuals (49 069 men and 60 151 women) over the course of 20 years of the KNHANES. Total vegetable intake decreased over time (Pfor trends < 0·001), specifically, steamed and salted vegetables (Pfor trends < 0·001). In contrast, Koreans consumed noticeably more raw vegetables from 1998 to 2017 (Pfor trends < 0·001). Vegetable intake at home significantly declined (Pfor trends < 0·001), while that eaten at restaurants or outside the home increased greatly (Pfor trends < 0·001). Over 20 years, Koreans have ingested decreasing amounts of vegetables, but the intake of raw vegetables has escalated. However, the location of vegetable consumption has changed, with an increase at both restaurants and outside the home (approximately 70·0 %).