The association between obesity and clinical as well as radiological outcomes in patients suffering non-traumatic intracerebral haemorrhage (ICH) remains unclear. The obesity paradox suggests a protective effect regarding in-hospital mortality. This study evaluates the impact of body mass index (BMI) on functional long-term outcome and bleeding volume in patients with non-traumatic ICH. A retrospective cohort study including all consecutive patients with spontaneous ICH treated at a tertiary referral centre between December 2017 and June 2021, aged 80 years or younger (n = 218), were included. Patients were dichotomized into overweight (OW, BMI ≥ 25 kg/m2) and normal weight (NW, BMI < 25 kg/m2). Functional outcomes were assessed by the modified Rankin scale (mRS), extended Glasgow Outcome Scale (GOS-E) and the National Institutes of Health Stroke Scale score (NIHSS) at 1, 3, 6 and 12-months follow-up. Bleeding volumes were calculated as ABC/2. Univariate and multivariate analysis were performed to assess clinical predictors of favourable outcome in the long-term. Of 218 patients (66.04 ± 15.18 years) suffering non-traumatic ICH, 115 (52.75%) were OW (29.72 ± 3.82). Female sex (p = 0.1), NIHSS (p = 0.69), cardiovascular risk factors (p = 0.55), ICH volume (p = 0.19), and presence of anticoagulation (p = 0.67) did not significantly differ between the OW and NW cohort. At discharge, functional outcome did not significantly differ between both cohorts (NW, mRS 3.92 ± 2.54 vs. OW, mRS 3.21 ± 2.43, (p = 0.28)). Multivariate analysis revealed that haemorrhage volume (p = 0.01) was the only robust risk factor to predict functional outcome after 1 year. Our data suggests that in ICH patients, neither obesity nor patient’s age are negative predictors for functional outcome in the long-term. Instead, bleeding volume is a robust risk factor predicting poor functional status after ICH. Therefore, prospective randomized trials analysing this coherence are highly warranted.