Entrepreneurial (i.e. business ownership) experience may enable some entrepreneurs to temper their comparative optimism in subsequent ventures. The nature of entrepreneurial experience can shape how entrepreneurs adapt. Using data from a representative survey of 576 entrepreneurs in Great Britain, we find that experience with business failure was associated with entrepreneurs who are less likely to report comparative optimism. Portfolio entrepreneurs are less likely to report comparative optimism following failure; however, sequential (also known as serial) entrepreneurs who have experienced failure do not appear to adjust their comparative optimism. Conclusions and implications for entrepreneurs and stakeholders are discussed.