The heightened concern for reduction of environmental pollution that has been occurring over the past decades has stimulated active continuing research and literature on the toxicity of heavy metals. While, the toxic effects of these substances is a widespread concern in the modern industrial context. Man has succeeded in poisoning himself with the two most polluted heavy metals (lead and cadmium) repeatedly throughout recorded history. Since heavy metals are probably the oldest toxins known to humans so this book aimed to evaluate the hazard of lead and cadmium on some constituents of blood and the testicular functions. Also, aimed to focus on the beneficial role of antioxidants (vitamin C and/or zinc) in retardation and regression of heavy metals problems.