AIDS is a major dreadful disease occurring in humankind. The virus attacks immune system, impairs the function of immune cells and is finally responsible for lowering the capability of it. Hence immune system fails to respond to various pathological conditions and infections. Due to the weakened immune system the body will be affected by various infections, there by leads to the death finally person. Several infections originate with AIDS known as opportunistic infections. They are so called as they take advantage of the opportunity to infect a weakened or immunodeficient host. Opportunistic diseases do not often affect healthy individuals with potential immune system where as individuals with weakened immune system are highly affected. HIV/AIDS remains the greatest public health crises in the world today.