The lipid profile is impacted by numerous factors. However, the seasonal variations in this profile have not been well-established in the southern hemisphere. The aim of this study was to determine the seasonal variation of the lipid profile in apparently healthy adults from Santiago, Chile. The study design was observational and prospective, involving 50 healthy volunteers of both genders, aged 23-62 years. The lipid profile was measured at monthly intervals over the course of one year. LDL was significantly higher in winter -spring than in summer- fall (p < 0.01). Conversely, HDL decreases significantly in winter (p < 0.05). We conclude that there are seasonal variations in the serum levels of LDL and HDL. The circannual pattern is characterized by increased levels of LDL in winter-spring and low levels of HDL in winter.