The development of sleep disorders, and specifically insomnia, has been linked to the exposure to different stressors. In this line, Coronavirus disease 2019 (COVID-19) outbreak caused by the new coronavirus SARS-CoV-2, has caused a huge impact on our environment, and has exposed healthcare workers to an unprecedented threat. In this study, we try to assess sleep quality and the development of sleep disorders in health personnel directly dedicated to the care of COVID-19 patients at the height of the pandemic, compared to the general population. A cross-sectional, anonymized, self-reported questionnaire survey was carried out at the “12 de Octubre” Hospital, in Madrid, Spain, during the outbreak of COVID-19, from March 1st to April 30th 2020. We compared two groups, healthcare workers who have treated directly COVID-19 patients versus non-healthcare workers. The questionnaire included demographic data, sleep related aspects, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI) and 17-items Hamilton Rating Scale (HRS). In total 170 participants completed the questionnaire successfully, 100 healthcare workers and 70 non-healthcare workers. Self-reported insomnia, nightmares, sleepwalking, sleep terrors and PSQI>6 were more frequent in the healthcare group (p < 0,05). Shift work was associated to greater risk when performing multiple logistic regression analysis. We observed that, during the outbreak of COVID-19, healthcare workers on the front line developed more sleep disturbances than non-healthcare professionals, and they had worse quality of sleep. Special attention should be paid to shift workers. Concrete protection and prevention measures for particularly exposed population should be considered in pandemic situations. •Health care workers dealing with COVID-19 patients show poorer sleep quality and higher incidence of self-reported insomnia.•Higher incidence of nightmares, sleepwalking and sleep terrors, is also shown in this group.•Shift work may encourage the emergence of these symptoms.•Special protection measures for particularly exposed groups should be considered in health threatening circumstances.