The moral responsibility theory of corporate sustainability argues that the extent of corporations' commitment toward sustainable development depends on how they perceive sustainability within the moral spectrum – from perfect to imperfect duties. This study assessed consumers' perceptions toward corporate sustainability and whether the moral spectrum toward corporate sustainability exists. After reviewing the corporate sustainability reports of 22 consumer product companies considered sustainable, 44 unique sustainable business activities were identified. These activities were then tested by a national sample of 271 US consumers. The results showed that participants perceived working conditions and environmental support activities to be the most important corporate duties (or perfect duties), followed by community development and transparency enhancement activities (or imperfect duties). This study also found differences in perceptions according to participants' demographic characteristics. These findings add knowledge to the area of corporate moral responsibility, and help firms have a clear understanding of consumers' expectations on corporate moral responsibility toward sustainable development. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment