We have tested the sensitivity of a recently published approach to combining clinical and EMG data in the 'research diagnosis' of ALS, in 55 consecutive patients clinically diagnosed with ALS. The application of this 'Awaji algorithm' to the revised El Escorial diagnostic criteria for diagnosis of ALS achieved a diagnostic sensitivity of 95% for definite ALS compared with 18% using the clinical El Escorial criteria and 53% when the EMG criteria as defined in the El Escorial criteria, were applied to the same dataset. This increased sensitivity was particularly relevant for bulbar onset patients (sensitivity improved from 38% to 87%) and for patients with El Escorial clinically possible ALS (from 50% to 86%). We suggest that, in future, investigators and triallists should use the Awaji algorithm superimposed onto the El Escorial criteria, in selecting patients for research studies.