This nationwide cross-sectional study aimed to compare Brazilian dietitians’ perceptions of quality of life before and during the pandemic, using a previously validated self-administered instrument WHO-QOL-BREF in Brazilian-Portuguese. Other sociodemographic variables and three questions about the Sars-CoV-2 period were included, and the instrument was applied using GoogleForms^®. Paired T-test, Chi-squared test, and Analysis of Variance were used for statistical analysis. A representative sample of 1290 dietitians from all the Brazilian regions answered the questionnaire. QoL before SARS-COV-2 (3.83±0.59) was statistically different from during the pandemic (3.36±0.66). Comparing before and during the pandemic, statistical differences were found for all variables and domains (worse in the pandemic period). The second domain (psychological health) was the most affected among Brazilian dietitians. The Sars-Cov-2 pandemic was associated with a negative impact on QoL of Brazilian dietitians, health professionals that faced changes in different areas of their lives.