Background: Since 2020, psychotherapists in Germany have been allowed to prescribe digital health applications for mental disorders (DHA-MDs). DHA-MDs were supposed to foster digitalization and improve access to mental health services. However, prescriptions of DHA-MDs are less frequent than expected. Objective: We aimed to investigate which characteristics of psychotherapists predicted perceived need for and prescribing of DHA-MDs among German psychotherapists. Methods: This study was a cross-sectional survey conducted in Germany. We contacted psychotherapists between January 2024 and April 2024 via professional associations, training institutes, or the social media platform X (formerly known as Twitter). We sent questionnaires to 1000 psychotherapy practices randomly selected from the registry of the National Association of Statutory Health Insurance Physicians. We assessed the characteristics of the psychotherapists, asked them to rate the perceived need for DHA-MDs on an 11-point scale, and documented their prescribing behavior. Linear and logistic regression analyses were performed to predict perceived need and prescribing, respectively. Results: A total of 321 psychotherapists participated. Perceived need was estimated as low (mean 2.1, SD 2.1). Among the 271 (84.4%) psychotherapists with valid data, 83 (30.6%) prescribed a DHA-MD to at least 1 patient in a regular quarter. As compared to a behavioral approach, a psychodynamic (b=–1.63; P<.001) or systemic psychotherapy approach (b=–1.48; P=.005) and higher age (b=–0.03; P=.007) negatively predicted the perceived need, while being a physician (vs psychologist; b=0.73; P=.02) and a psychotherapeutic and psychopharmacological treatment focus (vs psychotherapeutic alone; b=1.31; P=.04) positively predicted the perceived need. For prescribing DHA-MDs, odds were lower for psychotherapists with a psychodynamic, systemic, or other approach (vs behavioral approach; odds ratio [OR] 0.30, 95% CI 0.14-0.64). The odds were higher for psychotherapists with more than a half service mandate (vs less than or equal to a half service mandate; OR 2.99, 95% CI 1.50-5.97), working in a group practice or medical care center (vs single practice; OR 2.39, 95% CI 1.04-5.53), and being located in a rural community or small town (OR 2.74, 95% CI 1.27-5.94) or a medium-sized town (OR 2.67, 95% CI 1.21-5.92) compared to a large city. Conclusions: Professional group, psychotherapy approach, age, the size of service mandate, treatment focus, practice type, and community size predicted perceived need for and prescribing of DHA-MDs among psychotherapists. Our findings may inform stakeholders and decision-makers in health care and politics about where DHA-MDs have already been implemented in the landscape of mental health services.