A study to measure the concentrations of (lead and cadmium) in the blood and milk of cows grazing on (stray) waste in the outskirts of Al-Bayda city, Libya, and comparing them with cows grazing on natural pastures (inside farms). Lead and cadmium were measured using an atomic absorption instrument. The results of this study showed that the average concentration of lead and cadmium in the blood of (stray) cows was significantly higher (P<0.05) than (inside farms) 0.056 mg/l, 0.027 mg/l, 0.0023 mg/l and 0.000335 mg/l, respectively. The average lead concentration in (stray) cows' milk was 0.0565 mg/l, significantly higher (P<0.05) than 0.0322 mg/l for cows (inside farms). The average concentration of cadmium in cow's milk (stray) was 0.001933 mg/l, higher than that of (inside farms) 0.001853 mg/l. The average concentration of lead in the raw milk of the two groups was higher than the permissible amount of 0.02 mg/l, while the average concentration of cadmium in the raw milk of the two groups was less than the permissible value of 0.01 mg/l (FAO, 2011). Based on these data, there is an urgent need to prevent cows from grazing on waste.