Objective: Motor neurone disease [MND] encompasses broad cognitive impairments, which are not fully captured by most screening tools. This study evaluated the specificity and sensitivity of the Edinburgh Cognitive and Behavioral ALS Screen [ECAS] in detecting impairments in executive function and social cognition. Methods: Participants (MND = 64; Healthy Controls = 45) completed the ECAS and standard neuropsychology tests of executive function and social cognition. Sensitivity and specificity of the ECAS were assessed at three levels (ALS-Specific score, executive function domain score, individual subtests: social cognition, inhibition, working memory, alternation). Results: MND patients were impaired on standard social cognition, initiation, visuomotor alternation, and verbal learning tests but not on inhibition or working memory tests, relative to controls. ECAS results revealed that the ALS-Specific score was high in specificity but low-to-moderately sensitive in identifying social cognition, inhibition, and working memory deficits, and that both sensitivity and specificity were high for identifying alternation deficits. The ECAS executive function domain score was high in specificity but poor in sensitivity for all four executive function domain subtests. The individual ECAS subtests were highly specific with good sensitivity, but the social cognition subtest lacked sensitivity. Conclusions: Impairments in social cognition may go undetected when using the ECAS as a screening tool. Thus, social cognition may need to be considered as a standalone component, distinct from the other executive functions. In addition, the test itself may need to be adjusted to encompass other aspects of social cognition that are affected in MND.Key messagesCognitive screening tools are key to detect cognitive changes in MND, with the domains most affected being executive functions, language, and social cognition.The ECAS measure, developed for MND, has good specificity but lacks sensitivity to impairments in social cognition.Clinical implications are that cognitive impairments in social cognition may not be identified in MND patients by the ECAS.Adjustment to the ECAS cognitive screening tool widely-used in MND is suggested.