Background and objectives: A thesis is a requirement of the doctoral counselling psychology programme and plays an important role in forming an identity as a trainee counselling psychologist. While extensive research exists for doctorate experiences in general, less is known about the experiences of trainee counselling psychologists undertaking a thesis in the United Kingdom. The rationale behind this study is therefore to explore how trainee counselling psychologists perceive and make meaning of their experiences and how they go about writing their doctoral thesis. Method and analysis: A qualitative design was employed to answer the research question. Semi-structured focus group interviews were conducted with twenty trainee counselling psychologists who were either starting to write their thesis or at the stage of almost completing it. A grounded theory analysis was used in this study, which aims to generate a theory based on categories that have been discovered from the data. Several strategies were employed in this study to demonstrate the rigour and trustworthiness in a qualitative design. Findings: The results of this study show that two categories emerged from the data: (1) obstacles in completing a thesis and (2) positive perspective towards undertaking a thesis. The theory that emerged from this study shows that trainee counselling psychologists have both positive and negative experiences which appear to fluctuate during the process of undertaking a thesis and vary from person to person due to individual circumstances. It is vital not to envisage a dichotomy between the positive and negative experiences, which form a natural and necessary journey for all doctoral students. Conclusions: The trainee counselling psychologists' experiences of undertaking a thesis can be viewed as an emotional and multifaceted journey. Overall, the shared experiences of trainee counselling psychologists undertaking a doctoral thesis was a valuable contribution to this study.The paper discusses avenues for further research alongside some practical recommendations that might be useful for trainee counselling psychologists undertaking a doctoral thesis.