Objective Many anecdotal reports indicate the presence of ′long COVID′ - COVID-19-related symptoms weeks to months after the acute illness. However, frequency and symptom-pattern of ′long COVID′ in relation to acute disease severity are uncertain. As part of an ongoing, prospective cohort study we therefore conducted an online survey among adults 6 months after acute COVID-19. Methods The prospective online study Life&Covid is ongoing in Germany since May 2020. Participants were recruited 0 to 4 months after their SARS-CoV-2 infection und followed up by subsequent surveys. The survey 6 months after the infection was completed by 127 out of 148 individuals invited by email (86%). All grades of acute disease severity were included and 91% of the participants had been treated as outpatients during their acute illness. Results Six months after the infection, 67% of the study participants reported at least one symptom as a consequence of COVID-19. Exertional dyspnea (30% of participants), fatigue (25%) and diminished sense of taste/smell (19%) were the most common individual symptoms. At least one symptom, exertional dyspnea, and fatigue were reported more often after a severe acute illness, but diminished sense of taste/smell was unrelated to acute severity. Age group and sex did not associate with the frequency of symptoms at 6 months. Conclusions Based on this study, the prevalence of COVID-19-related symptoms 6 months after the infection is high. Some bias for overestimation may have affected this result. Nevertheless, ′long COVID′ requires attention in medical care and a better scientific understanding.