Introduction: Schizophrenia is a common disease with a high risk of comorbidity in both psychiatric and somatic diseases. Physical activity is proven effective in decreasing symptoms of schizophrenia and increasing overall health. Still it is not a natural part of the care in persons with schizophrenia. Aim: The aim of this study is to describe nurses' experience in using physical activity as complementary treatment in patients with schizophrenia. Method: Three focus groups with 12 participants were conducted. Qualitative content analysis was used to analyze data. Results: An uncertainty of the benefits was expressed through continuous query of questioning the result of physical activity. Nurses also expressed that physical activity was commonly used but questioned, in caring for persons with schizophrenia. However, it was perceived as a non-evidence based form of intervention and was used with uncertainty of the effects. Conclusion: The uncertainty of the benefits of physical activity is evident in nursing staff and pose a resistance to implement physical activity as a complementary treatment in schizophrenia. A new awareness of evidence based nursing is suggested to promote a wider and more offensive care to reduce patient vulnerability in persons with schizophrenia.