BACKGROUND: Rehabilitation after Knee Replacement (KR) surgery often entails an extensive rehabilitation in primary care but evidence-based high-quality guidelines are lacking. There is also a knowledge gap regarding current rehabilitation modalities applied in primary care in Sweden. This study aimed to (I) describe rehabilitation in primary care after KR and (II) explore physiotherapists' perceptions of patients' challenges during the rehabilitation. METHODS: A cross-sectional, web-based survey was conducted among Swedish physiotherapists working in primary care. Questions were categorical or open-ended and related to current rehabilitation practices, treatment modalities, and physiotherapists' perceptions of patients' challenges in rehabilitation after KR. Data were described descriptively and open-ended answers were analyzed with quantitative and qualitative content analysis. RESULTS: In total, 202 physiotherapists answered the survey. Rehabilitation focused on home exercises with recurrent physiotherapy visits. Common treatment modalities were knee range of motion exercises, strength training, and stationary cycling. Key rehabilitation challenges included the following categories: , , and . CONCLUSION: Rehabilitation after KR in Swedish primary care seems to be in line with previously recommended international treatment modalities. According to the physiotherapists in this study, some of the key challenges that patients faced were not being prepared for the severe pain regaining function and trust in the knee, balancing load/recovery, and resuming physically demanding activities.