Background: Aphasia is characterized by difficulties in connected speech/writing. Aims: To explore the differences between the oral and written description of a picture in individuals with chronic aphasia (IWA) and healthy controls. Descriptions were controlled for productivity, efficiency, grammatical organization, substitution behaviour and discourse organization. Methods & Procedures: Fifty IWA and 50 healthy controls matched for age, gender and education provided an oral and written description of a black-and-white situational drawing from the Dutch version of the Comprehensive Aphasia Test. Between- and within-group analyses were carried out and the reliability of the test instrument was assessed. Outcomes & Results: The language samples of the healthy controls were more elaborate, more efficient, syntactically richer, more coherent, and consisted of fewer spoken and written language errors than the samples of the IWA. Within-group comparisons showed that connected writing is more sensitive than connected speech to capture aphasic symptoms. Conclusions & Implications: The analysis of both modalities (speech and writing) at the discourse level allows one to assess simultaneously micro- and macro-linguistic skills and their potential interrelations in a given IWA. Connected writing appears to be more sensitive in discriminating IWA from healthy controls than connected speech. This method for analyzing language samples should, however, be used in conjunction with other assessment tools.