© 2022, Emerald Publishing Limited.Purpose: The purpose of this study is to assess the impact of Covid-19 on sustainable fashion consumption behavior by proposing a conceptual framework combining consumer-specific factors and product-specific factors with a special emphasis on consumer value perceptions. Design/methodology/approach: Theory of consumption value was integrated into the knowledge, attitude behavior model in the conceptual framework having consumer-specific and product-specific aspects. Perceived value (PERVAL) scale was used to measure value perceptions. The model was verified by a survey conducted among a random sample of 520 participants. The factors were extracted by using exploratory factor analysis and then confirmed by using confirmatory factor analysis. The hypotheses in the conceptual model were tested for different consumer groups, and the strength of the relationships was calculated by using multigroup analysis in structural equation modeling. Findings: It was observed the environmental concern raised the need for getting knowledge about the environment. The impact of environmental knowledge on the value perception of sustainable fashion products varied for the consumers affected by Covid-19 at different levels. Quality perception and price perception were influenced most by environmental knowledge in that order for the consumers with “high fear and uncertainty” and “low fear and uncertainty”. Similarly, the perceived emotional and social values were influential on purchase intention for consumers with high fear and uncertainty, whereas price and social value perceptions were influential for the consumers with low fear and uncertainty. Originality/value: This study is the initial study that investigated the impact of the Covid-19 pandemic on the consumption of sustainable fashion products. The integration of theory of consumption value into the knowledge, attitude behavior model allowed identifying the relationship between environmental issues and sustainable fashion consumption. Using the PERVAL scale for measuring perceived value, the study provided valuable insights for understanding the most important value dimensions for sustainable fashion products for consumer groups affected by Covid-19 at different levels. The results regarding the changes in the rankings related to the impact of environmental knowledge on dimensions of perceived value and the impact of perceived values on purchase intention enabled the integrated model to explain the attitude–behavior gap.