Summary Background Cutaneous reactions after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccines are poorly characterized. Objective To describe and classify cutaneous reactions after SARS‐CoV‐2 vaccination. Methods A nationwide Spanish cross‐sectional study was conducted. We included patients with cutaneous reactions within 21 days of any dose of the approved vaccines at the time of the study. After a face‐to‐face visit with a dermatologist, information on cutaneous reactions was collected via an online professional survey and clinical photographs were sent by email. Investigators searched for consensus on clinical patterns and classification. Results From 16 February to 15 May 2021, we collected 405 reactions after vaccination with the BNT162b2 (Pfizer‐BioNTech; 40·2%), mRNA‐1273 (Moderna; 36·3%) and AZD1222 (AstraZeneca; 23·5%) vaccines. Mean patient age was 50·7 years and 80·2% were female. Cutaneous reactions were classified as injection site (‘COVID arm’, 32·1%), urticaria (14·6%), morbilliform (8·9%), papulovesicular (6·4%), pityriasis rosea‐like (4·9%) and purpuric (4%) reactions. Varicella zoster and herpes simplex virus reactivations accounted for 13·8% of reactions. The COVID arm was almost exclusive to women (95·4%). The most reported reactions in each vaccine group were COVID arm (mRNA‐1273, Moderna, 61·9%), varicella zoster virus reactivation (BNT162b2, Pfizer‐BioNTech, 17·2%) and urticaria (AZD1222, AstraZeneca, 21·1%). Most reactions to the mRNA‐1273 (Moderna) vaccine were described in women (90·5%). Eighty reactions (21%) were classified as severe/very severe and 81% required treatment. Conclusions Cutaneous reactions after SARS‐CoV‐2 vaccination are heterogeneous. Most are mild‐to‐moderate and self‐limiting, although severe/very severe reactions are reported. Knowledge of these reactions during mass vaccination may help healthcare professionals and reassure patients. What is already known about this topic? In clinical trials, COVID‐19 vaccines were associated with cutaneous adverse events, especially local injection site reactions. Previous descriptions of cutaneous reactions beyond the injection site were case reports or mostly reported by non‐dermatologists and lacked clinical images. What does this study add? We describe and classify a large, representative sample of patients with unexplained skin manifestations after COVID‐19 vaccination, using consensus to define associated morphological patterns. We describe six morphological reaction patterns and herpesvirus reactivations, and their association with demographic factors and the medical record, and provide illustrations to allow for easy recognition. Linked Comment: V. Bataille and S. Puig. Br J Dermatol 2022; 186:15. Plain language summary available online