EXPERIMENTAL work on the relationship of psychological factors to ulceration has been confined to one aspect of this pathology, namely, the initiation of ulcers [1-11]. A second aspect of the problem of ulceration is to account for the chronicity of ulcers: why do some ulcers persist and do not recover ? Clinical observations suggest that emotional influences such as anxiety are involved in preventing or retarding the recovery from ulceration. In this connection Cushing [12] mentioned may easily be that highly strung persons, who incline to the form of nervous instability classified as parasympathetic (vagotonic), through emotion or repressed emotion, incidental to continued worry and anxiety and heavy responsibility, combined with other factors such as irregular meals and excessive use of tobacco, are particularly prone to have chronic digestive disturbances with hyperacidity often leading to ulcer effects (p. 33). Mikhail [13, 14] argued that conditioned anxiety was not involved in the initiation of gastric ulcer in rats. In these reports, however, the role ofanxietyin ulcer chronicity was not considered. The present study sought to investigate the chronicity aspect of ulceration to which surprisingly little attention has been paid. The method which has been used in Experiments 1 and 2 of this report is based on the following observations, (a) gastric ulceration in rats can be induced by restraint stress [15, 16]; (b) Brodie and Hanson [17] found that in the absence of a stressful agent, restraint ulcers recover almost completely within 72 hr following the termination of 24-hr restraint; (c) the recovery of stress ulcers can be delayed chemically by prednisolone (a glucocorticoid) injections [18]; (d) several investigators [6, 11] reported that conditioned anxiety and similar stressful procedures have ulcerogenic effects. It was claimed [8, 9] that even the presentation of a conditioned stimulus without shock reinforcement contributed significantly to the production of ulcers in a restraint situation. Similarly, Sines [19] mentioned that flashing light stimulation for 12 hr and intermittant loud sound stimulation for 12 hr have been used with Sprague-Dawley animals and have been found to produce lesions in the stomachs of about k of the animals stressed in this way (p. 396). Hence, if rats with restraint ulcers are exposed to conditioned anxiety, it should be possible to test whether or not anxiety delays the recovery of lesions. The time required for the recovery from ulceration can be assessed by killing experimental and control rats periodically and comparing the progress of lesion healing in these subjects as noted by Brodie and Hanson [17]. Bearing the above considerations in mind, work proceeded as follows. EXPERIMENT 1 Method Subjects. 20 male MNR rats [20] of 161-169 days of age, and 262.05 (S.D. : 15.20) g of weights were employed. The subjects were randomly and equally divided into experimental and control groups.