PROBLEM TO BE SOLVED: To provide a medical pressure-sensitive adhesive composition which is less likely to cause blister or skin rash, that is skin friendly, when adhered for a long time and which can form an easily peelable adhesive layer capable of not leaving any adhesive residue, while being sufficiently in close contact with a skin just after applied onto the skin.SOLUTION: There is provided a medical pressure-sensitive adhesive composition contains: a urethane resin (A)； a tackifier resin (B) having a softening point of 75°C or higher and having a hydroxy group； and an isocyanate curing agent (C). The composition has an adhesive force ratio [(X2)/(X1)] of an adhesive force (X2) to a stainless steel plate after 24 hours in a 23°C×50%RH environment to an adhesive force (X1) to a stainless steel plate after 20 minutes in a 23°C×50%RH environment of 0.8 to 1.5.SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】貼付直後から皮膚に十分密着しながら、長時間貼付時に、浮き、かぶれが生じ難く、すなわち皮膚を傷めず、糊残りせずに容易に剥離可能な粘着層を形成できる医療用粘着剤組成物、および医療用粘着シートの提供を目的とする。【解決手段】ウレタン樹脂（Ａ）、軟化点７５℃以上であり、かつ水酸基を有する粘着付与樹脂（Ｂ）及びイソシアネート硬化剤（Ｃ）を含有し、ステンレス鋼板に対する、２３℃×５０％ＲＨ環境下２０分後の粘着力（Ｘ１）と２３℃×５０％ＲＨ環境下２４時間後の粘着力（Ｘ２）との粘着力比［（Ｘ２）／（Ｘ１）］が、０．８～１．５である、医療用粘着剤組成物により解決される。【選択図】なし
