Herpes zoster can cause rare but serious complications; the frequency of these complications has not been well-described.We aimed to quantify the risks of acute non-postherpetic neuralgia (PHN) zoster complications, to inform vaccination policy.We conducted a cohort study among unvaccinated immunocompetent adults with incident zoster and age-, sex- and practice-matched zoster-free controls, using routinely collected health data from the UK Clinical Practice Research Datalink (years 2001 to 2018). Crude attributable risks of complications were estimated as the difference between Kaplan-Meier-estimated 3-month cumulative incidences in zoster patients versus controls. We used Cox models to obtain hazard ratios for our primary outcomes in patients with and without zoster. Primary outcomes were ocular, neurological, cutaneous, visceral and zoster-specific complications. We also assessed whether antivirals during acute zoster protected against the complications.178,964 incident zoster cases and 1,799,380 controls were included. The absolute risks of zoster-specific complications within 3 months of zoster diagnosis, were: 0.37% (0.34-0.39) for Ramsay Hunt syndrome, 0.01% (0.0-0.01) for disseminated zoster, 0.04% (0.03-0.04) for zoster death and 0.97% (0.92-1.00) for zoster hospitalisation. For other complications, attributable risks were: 0.48% (95% CI 0.44-0.51) for neurological complications, 1.33% (95% CI 1.28-1.39) ocular complications, 0.29% (95% CI 0.26-0.32) cutaneous complications and 0.78% (95% CI 0.73-0.84) visceral complications. Attributable risks were higher among patients >50 years old. Zoster patients had raised risks of all primary outcomes relative to controls. Antiviral prescription was associated with reduced risk of neurological complications (HR 0.61, 0.53-0.70).Non-PHN complications of zoster were relatively common, which may affect cost-effectiveness calculations for zoster vaccine. Clinicians should be aware that zoster can lead to various complications, besides PHN.