This article reports on findings from research aimed at investigating teacher collaboration and professional development in the workplace. It draws upon a broader study carried out in a school in Northern Portugal. Data were collected through questionnaires, semi-structured interviews and written reflective accounts. In total, 80 teachers participated in phase 1, 11 key informants participated in phase 2 and 10 teachers participated in an intervention/training project (phase 3). Findings suggest that problems and limitations in relation to collaborative work are situated at the organisational level, such as time and working conditions. Lack of training in collaboration, and issues such as motivation and personal difficulties, also emerged from the data. Teachers tend to stress the importance of interpersonal relationships at school, but they also identified formal meetings when they described the contexts and opportunities to work collaboratively in the workplace, namely department meetings and projects driven by central government or school administration initiatives. Implications for teacher collaboration and professional development are discussed.