Spray pyrolysis is one of the most widely used methods for carbon nanotube synthesis. This is mainly because of its scalability and - low cost of the carbon nanotubes produced. Spray pyrolysis is a promising method to create carbon nanotubes (CNTs) on various surfaces. By injecting metallocene-hydrocarbon solutions into a heated quartz reactor, catalyst particles and carbon nanotubes can be formed simultaneously. Factors that affect CNTs growth include the precursor concentration, injection rate and duration, carrier gas flow rate, substrate surface, growth temperature, and the composition of gases inside the reactor. The effect of these parameters on the morphology of CNTs synthesized by spray pyrolysis method is presented in detail.