The increased use of injectable substances in therapy has resulted in an increase in the number of allergic reactions. Such reactions have been known for many years in serum therapy. More recently there has been a marked increase in the parenteral administration of organ extracts, hormones and antibiotics and many allergic reactions have been reported following this form of therapy.The literature about allergic reactions in parenteral liver therapy is considerable. It appears that the most common symptoms are cutaneous manifestations such as urticaria, itching, erythema and angioneurotic oedema. Symptoms also arise from the mucous membranes; watery rhinitis, nasal obstruction, conjunctivitis and asthma are relatively common. Symptoms of various kinds such as dyspnoea, tightness in the chest, low blood pressure, shock and others have been described, but these are relatively rare. Fatal cases have occurred (Morgans, 1943; Falconer, 1945). Indisposition, nausea, vomiting and rise of temperature are also common side effects. Apart from these systemic reactions, local effects such as erythema, oedema and even necrosis around the site of injection are described (the Arthus' type of local allergic reaction).This survey shows that allergic reactions in parenteral liver therapy present a variety of symptoms ranging from slight local effects to extremely serious systemic reactions. The same patient may on one occasion present only an isolated symptom and on other occasions show a whole range of allergic symptoms of different degree from various organs.