The aim of this study was to evaluate the effect of freezing (- 80 degreesC) and the storage time of serum and plasma on the biochemical values of the lipid profile and US-CRP of the project Prevalence of Dementia in Elderly Residents in the Northern Zone of the City of Rio de Janeiro, obtained using the same methodologies in different laboratories, and also the influence of sample stability. The measurements were carried out at the Lipid Laboratory - LabLip, and stored for three years. They were returned to the Capsula laboratory using the same methodologies and the two results were compared. This study analysed the results in terms of the stability and storage of the samples, which led to the conclusion that the storage time of the frozen samples (- 80 degreesC) caused changes in the results for the total cholesterol and HDLc analyses. As for the US-CRP and triglycerides, they remained stable.