This work aimed to study the conversion of different types of plastic waste to liquid fuel oil by thermal and catalytic pyrolysis using bentonite and alumina as a catalyst in a laboratory scale semi-batch reactor. The pyrolysis of different types of plastic waste was carried out and optimum conditions were evaluated by changing various parameters such as pyrolysis temperature from 490°C to 550°C, using different types of catalyst such as bentonite or alumina, using different catalyst to plastic waste ratios of 1:2, 1:3, 1:4 and 1:5 and change of reaction time values from 16 to 48 minutes.