Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. To determine predictors of survival, we studied different parameters in our ALS Database including 479 patients. The effects of individual prognostic factors of survival were studied using Kaplan-Meier life table. The prognostic value of each factor of interest was expressed in terms of a hazard ratio. Survival from symptom-onset ranged from 4 months up to 11.9 years. Gender had no effect on survival in our cohort. However, age, site of onset, forced vital capacity, symptom duration and ALSFRS-R score at the first visit were independent prognostic factors in our population (log-rank p<0.01). The ratio of ALSFRS-R score between first symptom and first examination, during whole disease or within 100 days, correlates with survival time. We conclude that the ratio of ALSFRS-R score within 100 days is a useful parameter for clinical trials and daily clinical work in a tertiary ALS-clinic.