The paper's chief goal is to determine the impact of COVID-19 on consumer purchasing behaviour and purchasing decisions concerning selected factors affecting consumers when buying food products in chain stores. The research was conducted in V4 countries, and data were obtained from a questionnaire. Essential research methods, such as analysis, synthesis, comparison, induction and deduction, were used in the presented research. Selected basic methods of descriptive statistics, normality tests and correlation coefficients were also applied. After evaluating the results of the questionnaire and verifying the research hypotheses, the expected conclusion regarding the apparent impact of COVID-19 on consumer purchasing and decision-making was confirmed. The hypothesis focused on buying behaviour in relation to gender (p = 0.03665), and economic status (p = 0.0407) was confirmed, manifesting a statistically significant relationship between these factors. A statistically significant relationship between age and buying behaviour during the COVID-19 pandemic was not confirmed (p > 0.05). The research's benefit is identifying changes in buying behaviour and consumer decision-making during the COVID-19 pandemic, which is crucial information, especially for entrepreneurs who can thus adjust their business activities to the current customer needs.