Neem-based pesticides are shown to have pest-controlling abilities and appear promising in reducing pollution caused by agricultural activities as they are easily biodegradable. Azadirachtin (Aza) is the key ingredient of all neem-based pesticides. However, the use of neem pesticides is limited due to storage instability of pure Aza. In this work, for the first time, free-flowing fine powder of whole dry neem fruits (PNF) is developed without separately extracting Aza. The optimal particle size was found to be −85+100 mesh. The stability of Aza was found to be improved as it is in original form. The efficacy of treatment is high as other limonoids such as nimbin, salannin are also available in PNF. PNF is characterized by FTIR, XRD, BET surface area, particle-size distribution, and SEM. The stability of PNF was assessed by studying the effect of particle size, temperature, UV light exposure, and release study in buffered and natural water samples.