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 center dot 2%), mRNA-1273 (Moderna; 36 center dot 3%) and AZD1222 (AstraZeneca; 23 center dot 5%) vaccines. Mean patient age was 50 center dot 7 years and 80 center dot 2% were female. Cutaneous reactions were classified as injection site ('COVID arm', 32 center dot 1%), urticaria (14 center dot 6%), morbilliform (8 center dot 9%), papulovesicular (6 center dot 4%), pityriasis rosea-like (4 center dot 9%) and purpuric (4%) reactions. Varicella zoster and herpes simplex virus reactivations accounted for 13 center dot 8% of reactions. The COVID arm was almost exclusive to women (95 center dot 4%). The most reported reactions in each vaccine group were COVID arm (mRNA-1273, Moderna, 61 center dot 9%), varicella zoster virus reactivation (BNT162b2, Pfizer-BioNTech, 17 center dot 2%) and urticaria (AZD1222, AstraZeneca, 21 center dot 1%). Most reactions to the mRNA-1273 (Moderna) vaccine were described in women (90 center dot 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.