The laboratory exams are recognized as an important diagnostic tool in veterinary practice, especially in the elucidation of several diseases that assault companion animals, particularly dogs. Among these exams, serum biochemistry stands out, not only for its clinical importance, but also for its simple performance and incorporation to routine of veterinary clinical laboratories. In front of this importance and the great demand for serum biochemical tests in routine of small animals clinics, and considering the lack of information about the viability of blood, the aim of this study was to evaluate the stability of some blood components front to different temperatures and stock periods. For this, samples of blood serum of 10 healthy dogs were analyzed for determination of sodium, potassium, total calcium, phosphorus, cholesterol, triglycerides, total protein, albumin, creatinine, urea and activity of the enzymes aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase and creatine kinase, kept in different temperatures (25°C, 4°C, -4°C, 20°C and -70°C) and analyzed in different periods (just after sampling, 12 hours, 24 hours, 36 hours, 7 days, 15 days, 30 days, 60 days and 90 days after the sampling). As results, it was observed that samples kept to room temperature had no alteration in relation to serum activity of all appraised enzymes as well as to concentration of total proteins, albumin, cholesterol and phosphorus for seven days of storage. For temperature of cooling, the activity of the enzymes remained stable for 30 days with exception to activity of glutamyltransferase. Concentration of total proteins, albumin, triglycerides, phosphorus, potassium and creatinine were also stable for the same period. At freezing temperature -4°C, only the activity of creatine kinase was statistically different after 60 days of storage, and at temperature of -20°C the activity of gamma-glutamyl transferase suffered significant alteration after 30 days. Metabolic compounds and minerals, in both freezing temperatures, remain stable during the whole experimental period. At freezing temperature of -70°C, the activity of gamma-glutamyl transferase and aspartate aminotransferase suffered significant statistically alterations in early beginning of storage periods. Considering this, among the several temperatures of storage of dog's serum for biochemical analysis, the temperatures of freezing -4°C and -20°C provided a longer stability for studied parameters, staying those viable for 60 and 30 days, respectively.