Cytostatics in the platinum salts group enter into regimens that address several types of cancer: sarcomas, carcinomas (lung small cell and non-small cell, ovarian cancer), lymphomas, germ cell tumors. Platinum compounds have antitumoral activity by creating intrastrand and interstrand bridges and nonfunctional adducts in the DNA chains, acts that interfere with mitotic cell division. This group of drugs cause many side effects: nephrotoxicity, neurotoxicity, gastrointestinal toxicity (nausea, vomiting), ototoxicity and fluid and electrolyte disorders. In clinical use multiple chemotherapy regimens include drugs containing platinum ions: cisplatin, carboplatin, oxaliplatin. To monitor the efficacy of platinum salts authors present a method for measuring blood and urine levels of platinum. It was a facility used AAS (atomic absorption spectrometry) with Varian graphite furnace atomisation. Are presented the results obtained from a batch of patients treated with cisplatin and carboplatin at the Radiobiology Department of Fundeni Clinical Hospital. The method is useful for achieving an optimal therapeutic index in terms of minimizing adverse reactions.