This study examines the prevalence and the gender differences in the perceptions and experiences of flexibility stigma—i.e., the belief that workers who use flexible working arrangements for care purposes are less productive and less committed to the workplace. This is done by using the 4th wave of the Work-Life Balance Survey conducted in 2011 in the UK. The results show that 35% of all workers agree to the statement that those who work flexibly generate more work for others, and 32% believe that those who work flexibly have lower chances for promotion. Although at first glance, men are more likely to agree to both, once other factors are controlled for, women especially mothers are more likely to agree to the latter statement. Similarly, men are more likely to say they experienced negative outcomes due to co-workers working flexibly, while again mothers are more likely to say they experienced negative career consequences due to their own flexible working. The use of working time reducing arrangements, such as part-time, is a major reason why people experience negative career outcomes, and can partially explain why mothers are more likely to suffer from such outcomes when working flexibly. However, this relationship could be reverse, namely, the stigma towards part-time workers may be due to negative perceptions society hold towards mothers’ commitment to work and their productivity. In sum, this paper shows that flexibility stigma is gendered, in that men are more likely to discriminate against flexible workers, while women, especially mothers, are more likely to suffer from such discrimination.