With COVID-19, populations are facing unmet health needs due to fear of contagion, lockdown measures and overload of Healthcare services (HCS). The COCOS study aimed to investigate reduced healthcare access among Italian citizens, additionally looking for specific subgroups that will primarily need health services in the next future . A cross-sectional online survey was performed during the Italian lockdown between April and May 2020 . Descriptive, univariable and multivariable (logistic regression models) analyses were performed: results are expressed as Odd Ratios and Adjusted Odd Ratios (ORs and AdjORs). Totally , 1,515 questionnaires were collected . Median age was 42 years (IQR 23), 65.6% were females . Around 21.8% declared to suffer from chronic diseases . About 32.4% faced a delay of a scheduled Medical Service (MS) by provider decision , 13.2% refused to access scheduled MS for the fear of contagion, and 6.5% avoided HCS even if having an acute onset issue . Alarmingly , 1.5% avoided Emergency Department when in need and 5.0% took medications without consulting any physician: patients suffering from chronic conditions resulted to be more prone to self-medication (AdjOR [95% CI]: 2.16 [1.16-4.02] ). This study demonstrated that indirect effects of COVID-19 are significant . Large groups of population suffered delays and interruptions of medical services, and the most vulnerable were the most affected . Immediate efforts are needed to reduce the backlog that HCSs incurred in.