Background: One of the crises recently affecting human society is an emerging pandemic that has had a significant psychological impact on healthcare workers. Studies have shown that staff experience psychological disorders such as anxiety, depression, and insomnia when exposed to crises. Objectives: This study aimed to determine the association between health anxiety and the sleep quality of healthcare workers during crisis conditions. Methods: This cross-sectional, correlational descriptive-analytical study was conducted from late February 2019 to late March 2020. Using convenient sampling, 382 healthcare workers from medical universities in Golestan province participated in the survey. Data were collected via an internet link shared with participants through WhatsApp working groups. The instruments used in this research included demographic information, sleep quality, and health anxiety inventories. The data were analyzed using SPSS-21 with descriptive and analytical statistics. Results: Of the participants, 77.2% were women, 65.4% were single, 60.7% were nurses, and 64.4% had a bachelor's degree. The results revealed that 72.7% of the staff experienced moderate to high levels of anxiety. Regarding sleep quality, 28.3% (n = 108) of healthcare workers reported good sleep quality, while 71.7% (n = 274) reported poor sleep quality. Additionally, the results indicated a significant correlation between health anxiety scores and sleep quality scores (r = 0.129, P = 0.01). Conclusions: The results of this study showed that the critical conditions caused by emerging diseases have led to health anxiety among healthcare workers, negatively affecting their sleep quality. Therefore, medical center officials must address such psychological issues and implement preventive measures to maintain the mental health of healthcare workers.