Testicular cancer is the most common malignancy in young men and in recent decades its occurrence has been growing rapidly. Tumour development induces changes in cell metabolism that can be monitored by analysing the metabolites in biological samples of the subject. The aim of this study was to create a quantitative profile of free amino acids and elements in urine and levels of oxidative stress parameters in blood of men with testicular cancer and compare them with control subjects. In subjects with testicular cancer, significantly higher concentrations of aspartic acid, manganese and zinc were measured, as well as a higher activity of superoxide dismutase. On the other hand, concentrations of threonine, serine, histidine, cobalt and glutathione and total oxidant status were significantly lower in comparison to control subjects. Additionally, linear discriminant analysis (LDA) was performed to examine whether the created amino acid profile discriminated subjects with testicular cancer from control subjects and the results showed that the discrimination rate was 86%. In the urine of subjects with testicular cancer a qualitative profile of volatile organic metabolites was also created to detect which species, depending on their functional groups, can be detected in urine. GCMS analysis of urine detected about 200 peaks of volatile organic metabolites, and 123 of them were identified. The effect of cisplatin chemotherapy on the concentration of amino acids and elements in urine and on the parameters of oxidative stress was also estimated. After receiving chemotherapy, concentrations of the majority of amino acids and elements in urine and glutathione in blood plasma increased in comparison to values obtained before chemotherapy. One year after receiving chemotherapy the results showed that the concentrations of most amino acids and elements were similar to those measured in the control subjects, except for threonine, serine and mercury, which had significantly higher values, and manganese and platinum, which had significantly lower values than the control subjects. Results indicated a gradual metabolism recover following chemotherapy. The results of this research suggest that the development of a tumour in the testicles leads to a disorder in the citric acid cycle and the urea cycle. The obtained results can be used as a basis for further research on the role of the intermediates of the above-mentioned cycles in tumorigenesis, which could contribute to the possible discovery of new biomarkers for testicular tumours.