Six women had symptoms of immediate type allergic reactions such as localized oedema, urticaria and pruritus elicited at, or soon after intercourse. All had positive skin prick tests with dilutions of human seminal plasma. The symptoms failed to appear when the women's partners used a condom an intercourse. None of the women had IgE antibodies in serum against human seminal plasma when tested with the radioallergosorbent test. This type of allergic reaction is easily overlooked.