Several drugs can cause hypertension and/or blunt the effect of antihypertensive treatment. They can exacerbate a previously well controlled hypertension and/or render it resistant to therapy. Accordingly, drugs represent a common cause of resistance of hypertension to treatment. Identification of drug-related hypertension can be achieved with a thorough medical history targeted to ascertain concurrent therapies that are prescribed for conditions other than cardiovascular diseases. This can avoid prescribing a more aggressive antihypertensive treatment and may prevent embarking in costly and sometimes invasive diagnostic procedures. Drugs that commonly raise blood pressure include NSAIDs, steroids, oestroprogestinic agents, immunosuppressants, erythropoietin, inhibitors of angiogenesis, anti-HIV agents, and also some high-density lipoprotein-raising agents. As withdrawal of the offending drug is often impracticable, knowledge of the mechanism(s) by which each drug exerts its pressor effects may help selecting the most effective treatment. Purpose of this review is to examine the most common causes of resistant hypertension that are due to drugs or abuse of substances along with their underlying pathophysiological mechanisms. The strategy for selecting the most appropriate treatment and the reasons for 'a call of action' of research in this area are also examined.