Purpose: This study measured the quality of life in patients with amyotrophic lateral sclerosis (ALS). Methods: The participants consisted of consecutive patients with ALS who visited the neurology outpatient department from January to July, 2008. To collect the data, face-to-face interviews were applied at S national university hospital in Seoul. Using multivariate analysis, factors to predict QOL in ALS patients including demographic factors, functional independence, depression, anxiety, social support and quality of life were analyzed. Results: The final analysis included 69 patients. The mean score for the physical health and mental health components was $34.4{pm}21.3$ and $44.7{pm}20.6$, respectively. The mean score for the ALS functional rating scale was $24.3{pm}10.8$ out of 40. Anxious and depressed patients accounted for 44.9% and 71%, respectively. Quality of life in ALS patients was significantly affected by functional independence, depression and anxiety level. Conclusion: To improve the quality of life in ALS patients with declining functional independence, comprehensive interventions are necessary to manage depression and anxiety.