There are prevalent financial relationships between dermatologists and pharmaceutical companies in Japan. However, little was known about the extent of whole picture of the personal payments made to dermatologists by pharmaceutical companies. This study aimed to examine the personal payments to the board-certified dermatologists by the Japanese Dermatological Association from the pharmaceutical companies between 2016 and 2019. Using the publicly disclosed payments data by the pharmaceutical companies between 2016 and 2019, we evaluated the magnitude, prevalence, and trends in the personal payments made to all board-certified dermatologists for the lecturing, writing, and consulting compensations. The payments were descriptively analyzed overall and by dermatologist demographics. Additionally, the payment trends were assessed by generalized estimating equation models. Of 6883 active board-certified dermatologists, 3121 (45.3%) received a total of $33,223,806 personal payments between 2016 and 2019. The median per-physician payments and number of payments (interquartile range) were $1737 ($613–$5287) and 4.0 (2.0–10.0) over the 4 years, respectively. Only top 1%, 5%, 10% of dermatologists received 41.7% (95% confidence interval [CI] 38.2–45.1%), 76.9% (95% CI 74.7–79.1%), and 87.6% (95% CI 86.2–88.9%) of overall payments. The number of dermatologists receiving payments and per-dermatologist payments increased by 4.3% (95% CI 3.1‒5.5%, p < 0.001) and 16.4% (95% CI 13.5‒19.4%, p < 0.001) each year. The board-certification in dermatology-oncology, in cosmetic dermatology, and male sex were significantly associated with higher personal payments with relative monetary values of 2.29 (95% CI 1.65–3.19, p < 0.001), 3.16 (95% CI 1.89–5.26, p < 0.001), and 5.38 (95% CI 4.12–7.04, p < 0.001). Less than half of Japanese board-certified dermatologists received lower personal payments from the pharmaceutical companies than those to other specialists. However, these personal payments were increasingly more prevalent and greater over the 4 years.