Background - In 2019, a migrant camp on the Greek island of Samos designed for 650 people was home to a growing population of over 5500. We aimed to quantitatively describe living conditions and health needs in the camp. Methods - A questionnaire was designed with reference to international humanitarian standards, following a consultative process with the asylum-seeker population. Domains assessed included demographics, living conditions, safety/vulnerability, and health. The questionnaire was piloted and then conducted in June 2019 on a sample of asylum seekers. Results - Five hundred participants, predominantly from Afghanistan and the Democratic Republic of Congo (DRC). Of these, 79.4% lived in tents. Respondents cared for a total of 570 children; 20.6% of women were pregnant, 35.4% had experienced violence, 83% psychological distress, 71% skin disease, 66% diarrhoea and vomiting, and 64% respiratory disease. Accommodation, sanitation, and nutrition fell below internationally recognised standards, and poor access to water was significantly associated ( p < 0.001) with respiratory disease, diarrhoea and vomiting, skin disease ,and psychological distress. Conclusions - Living conditions in the Samos camp fall below basic humanitarian standards and are associated with poor health status. Further research is imperative to analyse and monitor the diverse, varying needs of asylum-seekers and inform policies to improve conditions.