Corona Virus Disease-2019 (COVID-19) is a global pandemic disease with a spectrum of clinical presentations ranging from asymptomatic to acute respiratory distress syndrome, and multi-organ failure. A case-control study was carried out on 250 COVID-19 patients. Socio-demographic data, clinical features, laboratory findings, and co-parasitic infections were screened to assess the effect of parasitic co-infection on COVID-19 severity. Patients were classified as 135 (54%) moderate, 82 (32.8%) severe, and 33 (13.2%) critical, according to the National Health Commission. COVID-19 was more prevalent in ages between 60 ys and 90 ys (38.4%), males (56.8%), rural areas (52.8%), workers (52.8%), and non-married subjects (54.4%). Lymphopenia and anemia increased with increasing severity of COVID-19. Regarding parasitic co-infection, 49.6% of patients had parasitic infections. The percentage of co-parasitic infections was 71.9%, 29.3%, and 12.1% in moderate, severe, and critical COVID-19 patients, respectively. Co-infections were more common in ages between 20 ys and 40 ys (54.0%), males (65.3%), urban patients (61.3%), workers (65.3%), and married patients (57.3%). The most detected parasites were Blastocystis hominis, Cryptosporidium spp., Entameba coli, and Cyclospora cayetanensis, which were almost mixed parasitic infection. There was an inverse correlation between co-infection with intestinal parasites and COVID-19 virus severity. Parasite-driven immunomodulatory responses may mute the hyperinflammation associated with severe COVID-19 virus infection.