OBJECTIVES: The current study scientifically capture the variations observed in the temperature and humidity levels in various pharmacy outlets in different part of Kerala and to study the real time effect of storage on the stability of Cephalexin tablet stored in these outlets METHODS: Adequate quantities of different brands of Cephalexin tablets were selected from hospital and community pharmacies located in different regions of Kerala. Samples collected from different time intervals were suitably coded and analyzed for all parameters RESULTS: Study was observed that, Mean Maximum Temperature was recorded more in Kannur (33.35C) and Kozhikode (32.44C) city as compare to Cochin (31.45C). The Mean Relative Humidity was recorded more at Cochin (86.75%) as compared to Kannur (84.5%) and Kozhikode (84.58%). The study data show that percentage strength was least in samples collected from Cochin compared with those collected from Kozhikode and Kannur. Mean kinetic humidity was more in coastal area, which may have accelerated the degradation of samples from Cochin. A significant statistical difference (p= 0.0000) was observed across brands in the potency of Cephalexin. Microbiological data showed significant reduction in zone of inhibition for samples collected from Cochin in comparison with other regions CONCLUSIONS: The study identifies the importance of storage conditions of antibiotics in pharmacies for the better pharmaceutical care. Improper storage can leads to therapurtical failure and adverse reactions to patients.