ABSTRACT This study explored possible impairments in the comprehension of nominal metaphors in five aphasic patients with semantic deficits and two with difficulties in lexical access. To this end, a set of four novel tasks was designed: two oral paraphrasing and two forced-choice tasks. The results support the claims of the Class-Inclusion Model and the Graded Salience Hypothesis, and showed that difficulties in the comprehension of these types of expressions are sensitive to certain features of metaphor vehicles, especially their ambiguity, level of conventionality and degree of semantic opacity. Similarly, they confirmed that metaphors understood as categorization statements require the undamaged processing of low-imageability words, as opposed to analogical metaphors, which comply with the assumptions of the Structural Mapping Model. Generally, patients with lexical impairments do not show difficulties in the processing of metaphorical expressions, while the performance of patients with semantic deficit is affected in accordance with their inability to understand abstract and low-frequency words.