Milk and dairy products are one of the chief sources of nutrition for human beings particularly for infant and children. Aflatoxin M₁ (AFM₁) a hydroxylated metabolite of aflatoxin B₁ found in milk and milk products causes serious health issues for human beings. The objective of this study was to evaluate the effect of storage on the level of aflatoxin M₁ in milk and other dairy products sold at retail stores of Tripoli Province, Libya. Selected samples (Skimmed and cream milk, infant milk formula, butter, cheese, Cheddar, spread and slice) were evaluated by using specialized RIDASCREEN AFM₁ competitive enzyme linked immune sorbent assay (ELISA) technique. Our investigation revealed that, the concentration of AFM₁ increased with the duration of storage. Furthermore, we found that the newly manufactured samples had very low concentration of AFM₁ and within the permitted range. Moreover, AFM₁ concentration in skimmed and cream milk having 6 month shelf life had 5.00 ngkg^-1 and 5.03 ngkg-¹ respectively. Furthermore, both the expired skimmed and cream milk had AFM₁ concentrations 121.8 ngkg^-1 and 108.18 ngkg^-1, respectively. In addition to that, we found that the levels of AFM₁ in different dairy products varies with different shelf lives (12 and 1 month), such as cheddar (5.0 and 72.79 ngkg^-1), Spread (5.30 and 60.03 ngkg^-1), Slice (5.50 and 61.18 ngkg-1). Additionally, infant milk formula with shelf life of 24 months and expired samples had AFM₁ less than 5.00 ngkg^-1 and 60.8 ngkg^-1, respectively. Based on our investigation, we found that the presence AFM₁ in milk and milk products at high concentration may cause serious illness to consumers’ health and the consequent economic losses.