Morbid jealousy is a potentially disruptive condition that has received little attention. A cognitive-behavioural formulation of morbid jealousy proposes that such individuals possess schema in which there is a perceived threat of loss of their sexual partner. An attentional bias in morbid jealousy was investigated by using a dichotic listening task and the modified Stroop test. Twenty subjects who had met criterion for morbid jealousy were compared with 20 control subjects. In the dichotic listening task, word pairs were presented to each ear simultaneously, and subjects shadowed one channel while identifying target words. Ten percent of the words presented to the non-attended channel were target words, of which half were jealousy-related and half were not. Subjects were not told that the target words were only presented in the unattended channel. In the modified Stroop test, subjects had to name the colour of a series of Os, colour words, emotional words, control neutral words and jealousy-related words. As predicted, jealous subjects showed a superior performance in detecting jealousy-related stimuli in the dichotic listening task and an impaired performance in the colour naming of jealousy-related stimuli in the modified Stroop test, compared to the control subjects and the control conditions. The results of this study add support to the formulation that morbid jealousy involves an attentional bias towards jealousy-related information and this may have clinical implications.