Purpose: The purpose of this study is to focus on the informal learning (IL) processes of teachers in primary and secondary schools in Spain. Its objective is to study the strategies currently used by teachers to generate IL, identifying the factors that condition such learning and the changes that must be introduced to enhance it. Design/methodology/approach: The methodology is qualitative, with information from interviews with school principals (n = 21) and teachers (n = 60) from 22 primary and secondary schools in Spain and from 3 discussion groups with experts (n = 17). The topics used refer to strategies to generate and promote IL and its conditioning factors. Findings: The findings suggest that, regardless of the stage (primary/secondary) and ownership of the centre (state/private), the teaching staff use IL strategies that, beyond individual actions, involve meeting, sharing and reflecting with other teachers. The challenge is that IL facilitates both professional development and the development and improvement of the organizations. School principals play a central role in achieving this relationship and promoting the institutionalization of changes and educational administration in facilitating the right conditions for their development and recognition. Research limitations/implications: Given that the participation of schools in the research was voluntary, as was that of the teachers who agreed to be interviewed, some bias may exist. To refine the analyses it would also have been interesting to contrast with the people interviewed some of the assessments which appeared in the focus groups. Finally, future work might focus on analysing in greater detail the effect of different management styles on IL. Practical implications: The results presented point to the need for decisive support from school leadership teams for collaborative work processes and joint reflection, which are one of the basic conditions for facilitating IL and, at the same time, for encouraging organizational learning. Furthermore, in the Spanish context, there is the challenge of combining the participation of teachers in formal training actions with the recognition of IL generated in the development of daily professional activity. Originality/value: The data provided complements and reaffirms the findings of research carried out in other types of organizations, at the same time highlighting the importance of horizontal relationships among education professionals and the difficulty of creating a solid foundation for organizational changes. Improvements are, on the other hand, highly conditioned by the role adopted by school principals.