Background: Consumption patterns of people around the world have been tremendously affected due to the COVID-19 outbreak since December 2019. Previous studies validated the influence of both internal and external factors on consumer behaviour. However, due to the lack of empirical research, this study explored the influence of external factor such as COVID-19 on consumer purchase behaviour, economic and financial situation. In addition, the study investigated how crisis perception and consumption pattern vary due to demographic variables. Methods: A convenience sampling technique was used and a total of 340 responses were collected from three countries, e.g., Bangladesh (n ¼ 129), India (n ¼ 122), and Pakistan (n ¼ 89) using a structured questionnaire. The respondents rated the items, collected from relevant past studies, on a 5 point Likert scale ranging from highly disagree to highly agree. Results: Exploratory factor analysis summarized all the measurement items into seven main factors from which two factors were removed due to low reliability. Except for the individual's financial situation, the overall mean values of the remaining factors were above 3.50 indicating a higher level of crisis perception and greater change in consumption patterns. Multivariate analysis of variance indicated that the factor scores were significantly different across countries, gender, education and income groups. In addition, Indian consumers were highly concerned and affected by COVID-19 followed by Pakistani and Bangladeshi consumers. In only one factor (e.g., an individual's financial situation), country and age had a significant interaction effect. Finally, the factors had significant difference among three categories of consumers (e.g., low, medium and high crisis perception). It indicates that consumers with higher crisis perception reported more behavioural changes due to COVID-19. Conclusions: Therefore, more COVID-19 crisis perception leads to significant changes in consumption pattern and the financial situation of the consumers. This study will enable academicians, marketers and decision-makers to understand different facets of consumer behaviour in three contagious countries namely Bangladesh, India and Pakistan in South Asia.