Objective To compare the sociodemographic and clinical profiles of patients with advanced cancer admitted to a tertiary palliative care unit before and during the COVID-19 pandemic. Methods This is an analysis of data from patients receiving care before (10/21/2019 to 03/16/2020) and during (09/23/2020 to 08/26/2021) the COVID-19 pandemic. Sociodemographic and clinical data were evaluated. Logistic regression analyses were used, with the odds ratio (OR) and 95% confidence interval (CI) as measures of effect. Results 673 patients were enrolled (204 in the pre-pandemic period and 469 in the pandemic period). The final logistic regression model demonstrated that patients admitted during the pandemic had a greater chance of having white skin (OR: 1.66 [95% CI: 1.15–2.39]), having a gastrointestinal tract cancer (OR: 2.95 [95% CI: 1.55–5.62]) and in skin, bones, and soft tissue (OR: 2.40 [95% CI: 1.13–5.08]), having received prior radiotherapy (OR: 1.83 [95% CI: 1.26–2.55]), and having a higher global PG-SGA SF score (OR: 1.06 [95% CI: 1.02–1.09]). Conclusion Ethnicity, nutritional risk, previous radiotherapy, and type of tumor were associated with advanced cancer during the COVID-19 pandemic. It is unclear what impacts the COVID-19 pandemic had on palliative care. This study presented findings based on one tertiary palliative care facility for patients with cancer. Give the limited literature on the subject, our comparative analysis of data serves as a starting point for a debate on this subject. More studies of a similar nature are needed to enable future comparisons and assist planning for other pandemics.