Venous thromboembolism is a common condition and low molecular weight heparins (LMWHs) are widely used for its treatment. Chronic kidney disease (CKD) is also a frequent disease especially in subjects with comorbidities admitted to internal medicine wards. LMWHs are eliminated by the kidney and their half-life is increased in renal impairment. Based on a series of available studies we analyzed the relationship between treatment with LMWHs and different degrees of renal impairment including end-stage renal disease (ESRD). In order to reduce haemorrhagic risk, the LMWH dose should be reduced in CKD, even if reducing LMWH dose could impair drug effectiveness. Further studies relating glomerular filtration rate to LMWH effectiveness and side effects are required.