Praziquantel is the drug of choice for the treatment of all forms of schistosomiasis. This review summarizes the main features of the drug, with special attention being given to those aspects that may be of interest to the practicing physician. After a brief mention of the history, the chemistry, the major available brands and their costs, doses and administration schedules are reviewed. Pharmacokinetics and drug interactions are analyzed and the low toxicity and mild side effects are stressed. A major weakness of praziquantel is its relative inefficacy against recent infections, a factor that may occasionally result in low cure rates in hyperendemic areas. Recent findings of schistosome isolates with a decreased sensitivity to praziquantel are discussed in the broader context of a possible emergence of drug resistance.