Abstract Study question What are parenthood intentions of reproductive-aged individuals without children in Belgium? Summary answer Our findings show that 63% of study participants were either actively trying to conceive or expressed an intention to have a child(ren) in the future. What is known already Over the past decades, there has been a noticeable trend marked by declining fertility rates and a delay in the onset of parenthood. Narratives promoting childbirth co-exist in parallel with an ongoing social debate questioning the ethical justification of bringing new life into the world, given concerns about overpopulation and climate change. Younger generations seem to be increasingly choosing to remain childfree. To date, most studies have used a dichotomy approach (yes/no) to assess parenthood intentions, which inadequately captures the complexities of individuals' real-life experiences. Study design, size, duration We conducted a cross-sectional survey study using convenience sampling. Non-pregnant individuals of reproductive age without children were invited to answer a self-administered questionnaire. A pilot study (n = 10) was conducted to assess the readability, clearness and the length of the questionnaire. Based on our sample size calculation we aimed to recruit 1067 participants (95% confidence level, 3% margin of error). Data collection was carried out between November 2023 and January 2024. Participants/materials, setting, methods The study population consisted of reproductive-aged (18-45 years) individuals without children residing in Belgium. Participants were recruited through a multi-modal recruitment strategy (flyers, social media, etc.). The questionnaire was available in Dutch, French and English and contained questions on socio-demographic characteristics, parenthood intentions (based on the taxonomy of reproductive intentions developed by Bola et. al. (2022)) and sources of fertility information. In addition, it also included the Cardiff Fertility Knowledge Scale (Boivin et. al. (2013)). Main results and the role of chance In our current study sample (n = 1826), 71% participants self-identified as female and 28% as male. The mean age of our study sample was 25 years (SD 5). Most participants were born in Belgium (95%), were in a relationship (64%) and had some form of higher education (74%). A limited number of participants (2%) had previous experience with fertility treatment. Most participants were classified as ‘desirers’ (63%; n = 1146/1826), of which 5% (n = 83/1826) were actively trying to conceive and 58% (n = 1063/1826) were planning to have child(ren) in the future. In addition, 9% (n = 158/1826) of our study participants were ‘avoiders’ who expressed their preference to not have any children in the future. The remaining participants were classified as ‘flexers’ (28%; n = 508/1826). This group encompassed participants that were unsure about their desire to have children in the future (18%; n = 337/1826), those who indicated to not want any children now (8%; n = 150/1826) and those that indicated to be undecided (1%; n = 21/1826). On average, participants expressed a desire to have 2 children (SD 0,8), indicated a preference to have their first child at the age of 28 (SD 5) and to have their last child at the age of 32 (SD 6). Limitations, reasons for caution Our study employed convenience sampling to recruit participants, therefore our reported results should be interpreted with caution. The use of social media for recruitment could have introduced a bias towards participants with higher levels of education. Wider implications of the findings While most participants expressed an intention to have a child(ren) in the future, a significant number also expressed the wish to remain childfree or indicated to be unsure about their desire to have children. More in-depth research would be of value to better understand the reasons behind parenthood intentions. Trial registration number Not applicable