Aims: In the last French study in 2007, the incidence of hospital admissions (HAs) related to adverse drug reactions (ADRs) was 3.6%. The objective was to assess the current ADR-HA incidence in France and to describe both its characteristics and preventability. Methods: A prospective multicentre study was conducted among randomly selected French public hospital medical wards (April-July 2018). Patients admitted during a week period were included. ADR-HA cases were collected by the French Regional Pharmacovigilance Centres network. An independent committee validated potential cases and ADR preventability. Results: ADR-HA incidence was 8.5% (95% confidence interval [CI]: 7.6-9.4%), increasing with age (3.3% [95%CI: 1.8-5.5%] ≤16 y vs. 10.6% [95%CI: 9.3-12.0%] ≥65 y). The most common ADRs were haemorrhagic events (8.8%), haematological disorders (6.5%), acute renal failure (6.3%), fluid and electrolyte disorders (6.0%), and falls (5.2%). New drugs were involved: targeted therapies (22.8% of antineoplastics), direct oral anticoagulants (29.6% of antithrombotics) and incretin-based drugs (20.0% of antidiabetics). ADRs were preventable in 16.1% of cases because the drugs involved had not been used in accordance with monographies, package leaflets or other therapeutic guidelines. The main situations of noncompliance addressed either dose or duration of use (27.9%), warning (23.2%), use precaution (18.6%) and inappropriate self-medication or misuse by patients (11.6%). Conclusion: In France, ADR-HA incidence dramatically increased over the last decade. A significant proportion was related to new pharmacological classes and considered as preventable. These findings should lead to in-depth thought on preventive actions on at-risk drug classes.