The objective of this study was to develop a process for the extraction of essential oil from Neemrnseed. The extraction was carried out using soxhlet and agitated mixing vessel extraction units. Inrnthe soxhlet extraction a n-hexane was chosen to determine the effect of time and particle size onrnyield of the extraction oil. In the agitated mixing vessel n-hexane and ethanol were used torninvestigate the effects of solvents, particle sizes, and temperatures (30, 40 and 50oC) on thernquality and yield. A general factorial design was applied to both extraction processes usingrnDESIGN EXPERT software and linear regression model was obtained growing the individualrneffect of time, particle size, temperature and solvent type as parameter and their interaction in thernentire extraction process. For the soxhlet extraction, the minimum oil yield has been determinedrnas 37.625% after the extraction time of 2hours with particle size ranges from 0.85-1.4mm andrnmaximum oil yield 46.545% was found at the extraction time of 6 and 8hours in a particle sizernranges from 0.425-0.75mm. Therefore, increasing extraction time and decreasing particle sizernwill increase the amount of oil extracted. In the batch experiment, results showed that thernmaximum oil yields were 33.19% for ethanol and 47.32% for n-hexane at 50oC, and 0.425-0.71rnmm particle size. The Neem oil was found to have a colour of golden yellow due to the presencernof Nimbidin. Based on psycho-chemical characteristics, analysis showed that increasingrntemperature decrease iodine value, but increase saponification, and acid value, which means thatrnhigher extraction temperature results in higher oil yield but lower oil quality. The roughrnprofitability evaluation indicates us this project is beneficial as it is clearly observed from therncost estimation, the rate of return on investment was calculated and has 79.45% and the paybackrnperiod tells us the plant return its total investment cost in one year.