Objectives We investigated the clinical characteristics of patients with stroke recurrence in the first year after cardioembolic stroke, and determined the predictors associated with recurrence. Design A prospective cohort study. Setting Multicentre study at the Fukuoka prefecture in Japan. Participants We enroled 2084 consecutive patients who were hospitalised in stroke centres within 7days of onset from June 2007 to October 2009. The clinical characteristics of patients were assessed on admission, and the clinical course of all patients was followed for 1year. Results Of all patients, 425 (234 men, 7611years of age) had cardioembolic stroke and were included in this study. Fifty-one patients (12%) suffered a recurrence during the follow-up period. Age (HR 1.04, 95% CI 1.01 to 1.06, p=0.014), and level of C reactive protein (HR 1.01, 95% CI 1.00 to 1.02, p=0.018) on admission were significantly associated with recurrence in the univariate analyses. Male gender (HR 0.61, 95% CI 0.35 to 1.05, p=0.076), body mass index (HR 0.94, 95% CI 0.87 to 1.01, p=0.093), hypertension (HR 0.59, 95% CI 0.33 to 1.06, p=0.079), diastolic blood pressure (HR 0.99, 95% CI 0.97 to 1.00, p=0.087) and haematocrit (HR 0.95, 95% CI 0.91 to 1.00, p=0.052) were marginally significant in the univariate Cox analyses. Multivariate Cox proportional hazards analysis showed that age (HR 1.03, 95% CI 1.00 to 1.06, p=0.031, per 1-year increase), and C reactive protein (HR 1.01, 95% CI 1.00 to 1.02, p=0.022, per 1mg/L increase) were independent predictors of a recurrence in the first year after cardioembolic stroke. Conclusions In patients with cardioembolic ischaemic stroke, age and C reactive protein are independent risk factors for recurrence in the first year after onset.