OBJECTIVE The aim of this study was to adapt the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ), developed for the evaluation of quality of life in amyotrophic lateral sclerosis (ALS) patients, into the Turkish society. METHODS This methodological study was conducted in 92 ALS patients registered in 2 chapters (Istanbul and Izmir) of Turkish ALS-Motor Neuron Diseases Association. The expert opinion and forward-backward translation methods were applied for the linguistic validity of the ALSAQ (long and short versions: ALSAQ-40 and ALSAQ-5, respectively). RESULTS In the analysis of internal consistency, the Cronbach's alpha reliability coefficient was .96 for the total scale, whereas it was between .88 and .98 for the 5 dimensions. The dimensions of the long form were correlated with the items of the short form. CONCLUSION The Turkish versions of the ALSAQ short and long forms are valid and reliable tools to be used in the assessment of the quality of life in ALS patients.