The present investigation was carried out with the objective to find out the effect of modified atmosphere and its duration on pathological parameters of two cvs (Hisar Safeda and Lucknow- 49) of guava (psidium guajava L.). Results showed that the duration of modified atmosphere had significant effect on pathological parameters. There was no decay loss in the fruits up to 4th day of storage and there a erfruit started decaying, which increased with increase in storage period. The minimum decay loss 6% and 7.50% was recorded on 8th day of storage in the fruits stored in modifi ed atmosphere. The decay loss 20.75% and 29.93% was recorded in control fruits in cvs. Hisar safeda and L-49, respectively on

5th day of storage and it reached to 100% on 8th day of storage in both the cvs. Diff erent types of fungi i.e Phoma spp., Penicilium spp., Aspergillus spp., Colletotrichum spp. have been identifi ed throughout the storage period that caused decay loss in guava in both the cvs Hisar Safeda and L-49 (Sardar).