This is a case series of two convalescent patients with COVID-19 who, after treatment, had improved symptoms and resolution in follow-up lung CT scans. Three consecutive throat swabs and one anal swab taken during the follow-up period were all negative for viral RNA, however, in both cases, induced sputum was positive for viral RNA. The authors conclude that detection of SARS-CoV-2 RNA is more effective in induced sputum than throat swabs for convalescent patients. Furthermore, induced sputum is simple, non-invasive and poses less risk of nosocomial transmission to medical staff. Further testing is recommended to validate the clinical applicability of the sputum sampling method.