The performance of 185 focal brain-damaged patients on two non-verbal constructive tasks ('Copying Drawings' and 'Copying Drawings with Landmarks') was evaluated with regard to three variables: laterality of cerebral lesion, intrahemispheric locus of lesion, and coexistence of mental deterioration. The aim of the study was to assess the relationships between each of these variables and both the incidence and severity of constructional apraxia. Different evaluations were carried out in order to partial-out the possible interference of unilateral spatial neglect. Results showed that, regardless of whether faults attributable to unilateral spatial neglect were penalized or not: right brain-damaged patients performed slightly worse and showed a higher percentage of pathologic performances than left brain-damaged patients; subjects with parietal--and particularly with right parietal--damage obtained the poorest mean scores and exhibited the highest incidence of apraxic performances; and coexistence of mental deterioration was the most relevant variable associated with global decay of constructive scores and incidence of constructional apraxia.