COVID-19 is a severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). Deficiency of zinc has been supposed to contribute to loss of smell and taste in COVID-19 patients. Our study aimed to assess the serum zinc levels among patients with COVID-19 of various severities, with and without olfaction dysfunction, and to evaluate the effect of zinc therapy in recovery of smell dysfunction among such patients. This study included 134 patients; real-time reverse transcription-polymerase chain reaction (rRT-PCR) proved SARS-CoV-2. Serum zinc levels were measured for all infected patients. One hundred and five patients were detected to have anosmia and/or hyposmia and were categorized randomly into 2 groups; the first group included 49 patients who received zinc therapy and the second group included 56 patients who did not received zinc. All patients were followed up for the recovery duration of olfactory and gustatory symptoms and duration of complete recovery of COVID-19. Olfactory dysfunction was reported in 105 patients (78.4%). Serum zinc levels were not significantly different between the patient subgroups regarding disease severity or the presence or absence of olfactory and/or gustatory dysfunction (p ˃ 0.05). The median duration of recovery of gustatory and/or olfactory function was significantly shorter among patients who received zinc therapy than those who did not received zinc (p < 0.001), while the median duration of complete recovery from COVID-19 was not significantly different among the two groups (p ˃ 0.05). Although the zinc status of COVID-19 patients did not exhibit a significant role in development of anosmia and/or hyposmia or disease severity, zinc therapy may have a significant role in shortening the duration of smell recovery in those patients without affecting the total recovery duration from COVID-19. © 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.