Objective: Research has shown that therapists can develop a positive therapeutic relationship in the Internet setting and that the therapeutic relationship plays a role in treatment outcome. However, little is known about how therapists foster a positive therapeutic relationship in the Internet setting. Therefore, the current study assesses the extent to which therapists apply techniques that are recommended in the face‐to‐face setting when communicating with participants of an Internet‐based cognitive behavioural therapy (iCBT) intervention. Method: Qualitative content analysis was conducted to analyse therapists' messages sent to clients during the course of an asynchronous, text‐based iCBT intervention for caregivers of people with dementia. A total of 216 written messages from four therapists to 27 participants were analysed. Based on the motivational attunement framework of therapist behaviour, a deductive coding system was developed, and the intercoder reliability was satisfactory. Results: Through qualitative content analysis, a variety of techniques were found in the therapeutic messages: 12 main categories and six subcategories of therapeutic techniques that satisfy the four basic needs according to Grawe were identified. Therapists most frequently addressed the need for attachment (41%), followed by orientation and control (28%), self‐esteem (24%) and pleasure (7%). Conclusions: The results indicated that online therapists implemented many of the techniques that are recommended and applied in the face‐to‐face setting to foster a positive therapeutic relationship. Results can be used to develop training for online therapists and manuals for Internet interventions.