Objectives: The aim of this study was to assess back pain and its relation to physical activity as well as Internet addiction among Polish university students during the COVID-19 pandemic. Methods: The research was conducted via the Internet in student groups of three universities in Poland (141 people). Back pain was examined by ODI-The Oswestry Disability Index and NDI-Neck Disability Index. The Polish-language International Physical Activity Questionnaire (IPAQ) was used to assess physical activity and the level of Internet addiction was tested using the Kimberly Young Questionnaire. Results: The respondents mostly suffered from pain originating in the cervical spine. In the study group, only every fifth person had a high level of physical activity. Sex differentiates the level of the measures considered. Sitting in front of the computer affects the pain in the spine. Conclusions: Research results suggest that the pandemic is negatively affecting students. Frequent occurrence of back pain is observed with a simultaneous low level of physical activity. Maintaining regular activity during a pandemic, at least at home, is an indispensable preventive measure for physical health.