Objectives: Guidelines advise promoting a healthy lifestyle among patients with fertility problems as the lifestyle of women and men proved to be associated with their fertility. Australian fertility nurses were shown to lack access to structured lifestyle modification programmes, although they value healthy lifestyle promotion. This study aimed to examine whether gynaecologists also value promoting a healthy lifestyle and whether structured lifestyle modification programmes are available in Belgian fertility clinics. Design: An observational study was conducted among health care professionals (HCPs) working in Belgian fertility clinics. Participants/Materials, Setting, Methods: An Australian questionnaire on attitudes and practices related to promoting a healthy lifestyle among patients with fertility problems was reciprocally back-to-back translated and three open-ended questions were added. All HCPs of Belgian fertility clinics, including gynaecologists, fertility nurses/midwives, psychologists, and embryologists, were invited by e-mail to complete the questionnaire online. Responses to closed and open-ended questions were analysed with, respectively, descriptive statistics and qualitative thematic analysis. Finally, differences in perspectives between different groups of HCPs were explored. Results: A total of 50 fertility nurses/midwives, 42 gynaecologists, and 19 other HCPs completed the survey ( n = 111). Regarding attitudes, all respondents valued informing patients about the impact of lifestyle on fertility. The vast majority of HCPs ( n = 96; 86%) stated that fertility clinics have the responsibility to address unhealthy lifestyles prior to offering fertility treatment. Fertility nurses/midwives were significantly more likely than gynaecologists to state that fertility clinics have this responsibility ( p = 0.040). Regarding practices, the patient’s lifestyle was most commonly discussed by the gynaecologist ( n = 107; 96%) during the first appointment ( n = 105; 95%). The lifestyle factors that were ...