Background: Verb processing is largely described across languages as being impaired in agrammatic aphasia, i.e., non-fluent aphasia with so-called “telegraphic style”. Although both lexical and morphosyntactic errors have been reported in the literature, this paper questions the claim that impaired access to verbs is a hallmark of this clinical syndrome.Aims: The present study aims to assess how agrammatic verb processing is impaired in two languages with distinct grammatical properties: Basque and French, and to test hypotheses that suggested an access deficit to verbs on this new database. Moreover, the nature of agrammatic verb errors is analysed from an interdisciplinary neuropsycholinguistic perspective according to which aphasic symptoms should be interpretable at different levels of organisation of language processing involving neural, cognitive and linguistic aspects.Methods & Procedures: A protocol built on Basque and French grammatical properties was designed in order to assess whether errors are specific to verbs, whether they are lexical or morphosyntactic and whether the verb argument structure complexity increases lexical and morphosyntactic processing difficulties, in both production and comprehension. One Basque-speaking and one French-speaking patient with agrammatism and matched controls were assessed on various oral tasks (object and action naming; sentence production and comprehension; prepositional phrase production), each of them containing 20 pictures displayed on a computer. Data were collected using a digital recorder.Outcomes & Results: Results show that agrammatic speakers produced many lexical verbs of every argument structure type. Errors were specifically morphosyntactic and increased with the verb argument structure complexity. However, verb errors were different in Basque and French due to their distinct morphosyntactic properties. In addition, whereas errors appeared in French in the use of prepositions, case morphology was well preserved in Basque, raising the issue of considering distinct neurocognitive mechanisms underlying different morphological systems.Conclusions: This paper supports the view that Basque and French agrammatic data collected from this study do not result from a lexical-access deficit. However, this interpretation depends on how one considers inflected verbs to be processed (endolexicon or exolexicon), as addressed in the discussion. In conclusion, a “post-lexical access” deficit is rather suggested, that is prior to morphophonological encoding, and affects abstract morphosyntactic operations required to implement the verb argument structure.