Most women experience some premenstrual symptoms during their reproductive years. Yet, this is an under-researched health issue, particularly in the context of work. This study aimed to: (i) understand the prevalence and severity of premenstrual symptoms experienced by working females, and their association with key work outcomes; (ii) explore factors that may be influencing these symptoms and their severity; and (iii) examine how organizations might help staff with premenstrual symptoms that may be impacting their working lives. An online, anonymous survey collected quantitative and qualitative data from 125 working women in the UK. Over 90% of the sample reported some premenstrual symptoms; 40% experienced premenstrual symptoms moderately or severely. Higher symptom severity was significantly (p < 0.05) associated with poor presenteeism, intention to reduce working hours, and higher work absence (time off work, being late, leaving early). Moderate/severe symptoms were significantly associated with several individual-related variables: lower perceived general health, higher alcohol consumption, poorer sleep quality, anxiety, depression, hormonal contraception, and using fewer coping approaches towards premenstrual symptoms (avoiding harm, adjusting energy levels); and work-related variables: poorer work–life balance, lower levels of psychological resilience, higher perceived work demands, less control over work. Disclosure of premenstrual symptoms and sickness absence because of premenstrual symptoms was very low, typically because of perceptions of appropriateness as a reason for work absence, gender of line managers (male), and it being a personal or embarrassing topic. Staff with moderate to severe premenstrual symptoms were statistically more likely to disclose reason for absence than those with milder symptoms. Recommendations and suggestions for employers and line managers include the need to train staff to improve knowledge about women’s experience of premenstrual symptoms, to be able to communicate effectively with women and to provide tailored support and resources for those who need it. Implications for future research, policy and practice are discussed.