A field test of Motto and colleague’s Risk Estimator for Suicide selected a subset of 593 psychiatric patients with major or chronic affective disorder.Fourteen patients (2.4%) in their sample & 136 (4.9%) in Motto’s sample died by suicide within 2 years. The authors compared observed & expected frequencies of suicide using the variance test for homogeneity of the binomial distribution. Their findings raise questions about Motto’s scale but do not definitively invalidate it.