Aim/Purpose This study aimed to explore individual variation in doctoral candidates' perceptions about research writing and themselves as writers (research writing perceptions) across three countries (Spain, Finland, and the UK) and the relationship with doctoral candidates' research conditions and social support. Background The present study employed a person-centered approach to identify profiles among doctoral candidates' in relation to their research writing perceptions and the association between these profiles and research conditions and experiences (e.g., thesis format, thesis language, enrollment modality, phase of the doctorate, number of publications, and drop-out intentions) and perceived social support from supervisors and research community. Methodology 1,463 doctoral candidates responded to the Doctoral Experience survey. EFA and CFA were used to corroborate the factor structure of the research writing scale. Research writing profiles were identified by employing cluster analysis and compared regarding research conditions and experience and both types of social support. Contribution This study contributes to the literature on doctoral development by providing evidence on the social nature of doctoral candidates writing development. It is argued that doctoral candidates perceptions of writing are related to transversal factors, such as doctoral candidates researcher identity and genre knowledge. It also shows that most candidates still lack opportunities to write and learn to write with and from other researchers. Findings Three writing profiles were identified: Productive, Reduced productivity, and Struggler profiles. Participants in the Productive profile experienced more re-searcher community and supervisory support and had more publications, Struggler writers reported drop-out intentions more often than participants in the other profiles, and Reduced productivity writers were more likely to not know the format of the thesis. The three profiles presented similar distribution in relation to participants country, the language in which they were writing their dissertation, and whether they were participating in a research team. Recommendations for Practitioners Supervisors and doctoral schools need to be aware of difficulties involved in writing at the PhD level for all doctoral candidates, not only for those writing in a second language, and support them in developing transformative research writing perceptions and establishing collaboration with other researchers. Re-search teams need to reflect on the writing support and opportunities they offer to doctoral candidates in promoting their writing development. Recommendations for Researchers Further studies should take into account that the development of research writ-ing perceptions is a complex process that might be affected by many and di-verse factors and vary along the doctoral trajectory]. Future Research Future research could explore the influence of factors such as engagement or research interest on doctoral candidates research writing perceptions. The field could also benefit from longitudinal studies exploring changes in doctoral can-didates research writing perceptions.