Objectives: The objective of this study was to explore therapists' new-found experiences of what works in successful cases of teletherapy. Design: This was a qualitative study of therapists' experiences, making their implicit knowledge explicit and systematised. Methods: Twelve therapists were recruited via posts on social media and via the interviewers' professional networks. The therapists were interviewed at their office or via Zoom using a semi-structured interview guide. The interviews were analysed using inductive, reflexive thematic analysis. Results: The therapists described a number of interacting favourable factors, together contributing to successful remote treatments. Establishing a good therapeutic relationship and cooperation was a general success factor common to in-person and remote treatments. Specific factors included well-functioning communication technology, co-creating a sense of co-presence, safeguarding therapeutic boundaries adjusted to the remote setting, finding ways of compensating for the loss of several cues available in an in-person setting and the patient being motivated for a remote therapeutic endeavour. Conclusions: In the successful cases, therapists in this study seem to have developed specific skills to counteract the inherent challenges and to benefit from the advantages specific to the remote setting. In the post-pandemic era, when hybrid and remote therapeutic modalities become increasingly common, these specific skills and mechanisms have to be included in psychotherapy training programmes, supervision and continuing education.