The authors evaluated the caregiver time for 70 patients with ALS. The mean number of caregivers per patient was 2.0 (SD 1.3). Caregiver time increased with worsening of disability (p = 0.0001). The most time-consuming duties were housekeeping, feeding, and toileting. With worsening of patients' disability, families relied increasingly on paid caregivers. Caregiver time is a hidden cost of ALS care and is a major burden for caregivers.