We assessed the prognostic value of muscle ultrasonography in 31 patients with amyotrophic lateral sclerosis (ALS) and compared it with accepted prognostic variables like functional capacity (measured with the ALSFRS-R rating scale) and muscle strength. Each patient was examined once. The following ultrasonography parameters were determined: muscle thickness, echo intensity (EI) and the presence of fasciculations. Correlations between baseline measurements, preslope values and survival were calculated. EI, disease duration, muscle strength preslope and ALSFRS-R preslope correlated with survival. Using a stepwise multivariate analysis, the combination of EI preslope and ALSFRS-R preslope was shown to have the best predictive value for survival.