Introduction: COVID-19 has a relationship with patients’ demographic characteristics as well as their underlying diseases. This research has been conducted to evaluate factors' effect on Covid-19 patient's hospitalization rate and period in Hormozgan, Iran. Materials and Methods: The inclusion criteria of this retrospective study included all patients diagnosed as COVID-19 Patients after PCR who were referred to Covid-19 hospitals from February 2020 to June 2020 in Hormozgan province, Iran. After the completion of the consent form and observing ethical principles, 3480 patients' information was collected through the interview by Medical care monitoring center unit experts. The checklist was designed according to COVID-19 guidelines and approved by the World Health Organization and Iran Ministry of Health and Medical Education. The studied variables included gender, age, patients’ residence place, smoking history and medications use history, pregnancy, referral type to hospital, contact history with COVID-19 patients, early symptoms, gastrointestinal symptoms, intubation, Po2 level, history of cancer, chronic liver diseases, diabetes, chronic blood diseases, HIV/AIDS, acquired or congenital immunodeficiency, cardiovascular diseases, chronic kidney diseases, dialysis status, asthma and other chronic lung diseases, and chronic neurological disorders. These data were analyzed using descriptive (average-standard deviation-percentage) and analytical (including Chi-square, t-test, and regression tests) statistics with SPSS Ver.23 software. Results: In this study, 3480 COVID-19 patients including 1852 male patients (53.20%) with a median age of 43.11±21.72 and 1628 female patients (46/80%) with a median age of 44.86±22.40. The median age of men was significantly lower than the women's median age (P= 0.02). The duration of hospitalization of male and female patients was reported 2.64±4.14 and 2.76±4.297, respectively which was not statistically significant. The death rate of patients in our study was 6.6%. Conclusion: The results of this study also showed that the hospitalization period of HIV-positive patients and patients with cardiovascular and pulmonary diseases is much longer than other people, which imposes many human and financial costs on the country's health care system. Therefore, to maintain individual health and help improve the critical condition of the virus, it is better to develop and apply stricter protocols to prevent further outbreaks of the disease and check underlying diseases of people suspected to have Covid-19. These results can improve health care system planning and improving medical services presented to covid-19 patients.