OBJECTIVE To determine the frequency of shoulder pain in our amyotrophic lateral sclerosis (ALS) population and to explore potential associations with demographic and clinical features. METHODS We retrospectively reviewed the medical records of 193 patients with ALS patients seen at the Lahey Clinic between 2005 and 2009. Patients were categorized by the predominance of upper and lower motor neuron signs and the body regions initially involved. The frequency of shoulder pain was identified in each of these subgroups. RESULTS Forty-five (23%) of the 193 patients reported shoulder pain at some time during the course of their illness. Age, gender, manual labor, prior shoulder problems, ALS phenotype, and initial region of involvement were not correlated with shoulder pain. Patients with shoulder pain were more likely to develop proximal arm weakness during their illness and to report pain elsewhere. CONCLUSIONS Despite the limitations posed by this retrospective study, it underscores the prevalence of shoulder pain in patients with ALS. Further studies to identify risk factors, mechanisms of, and treatments for shoulder pain in patients with ALS may benefit this population.