Background: With the aging population and the ongoing pandemic, elderly patients have accounted for a large proportion of ICU admissions. The aim of this study was to explore current challenges in the nursing of elderly patients with severe COVID-19 through the experience of frontline nurses. Methods: A qualitative descriptive design was used. In-depth and semi-structured interviews with 18 ICU nurses were conducted to explore the experience of providing care for elderly patients with severe COVID-19 in the Omicron wave. Traditional thematic analysis was applied. Results: Three themes emerged as follows: (1) No plan survives first contact with the enemy, (2) Expectations vs. Reality, (3) Difficult to cover all aspects. Conclusions: Challenges can be encountered in different stages of providing care for elderly patients with severe COVID-19, including the preparation and training of knowledge and skills in the early stage, the challenges posed by old age in the diagnostic and treatment stage, and the challenges of psychological care and rehabilitation care.