Pre and post-harvest diseases have been identified as serious constraints to the quality, shelf-life and economic value of underground vegetables. The present study was carried out with the objective of assessing the incidence, severity, spatial and seasonal distribution of fungal and bacterial diseases on carrot (Daucus carota L.), beetroot (Beta vulgaris L.), sweet potato (Ipomoea batatas L.) and elephant foot yam (Amorphophallus paeoniifolius) in Warangal district, Telangana state, India. Systematic surveys using field and market approach were conducted from May 2024 to April 2025 from eight sites selected randomly out of which four were major markets and the other four were adjacent cultivation fields. Five thousand seven hundred sixty (5,760) vegetables were collected consisting of 2,808 healthy and 2,952 diseased specimens. Maximum disease incidence (55.4 ± 3.7 %), disease severity (3.32 ± 0.34) and Percent Disease Index (PDI) (66.5 ± 4.1%) was observed in sweet potato, while the elephant foot yam showed minimum disease incidence (48.1 ± 2.9%) and PDI (56.0 ± 3.3%). In the case of all the studied crops, maximum disease incidence, disease severity score and PDI was observed as 51.3 ± 3.3%, 3.03 ± 0.30 and 60.5 ± 3.7%, respectively. Among the surveyed locations, maximum disease incidence (53.4 ± 3.6%) and PDI (64.6 ± 4.0%) were recorded in Warangal district. Incidence of disease increased from 43.2 ± 2.6% in May 2024 to 57.3 ± 3.5% in October 2024 and maximum monthly PDI (69.2 ± 4.3%) and disease severity (3.46 ± 0.34) were also observed in October. The maximum prevalence of disease symptoms were soft rot (20.73% [612 samples]), dry rot (14.16%), surface discoloration (11.42%) and black lesions (9.86%). The maximum disease features observed in this study included formation of lesions (82.4 ± 4.1%), dark brown to black colour of lesion (74.8 ± 3.6%) and softening of the tissues (65.9 ± 3.4%). GIS mapping showed Warangal and Hanumakonda as major disease spots, while Narsampet showed comparatively lower disease incidence. Environmental monitoring showed that high temperature, rainfall and relative humidity during monsoon and post-monsoon seasons correlated with maximum disease incidence and severity. In storage surveys of 120 respondents, 78.3% harvested manually, 56.7% had mechanical injuries, 52.5% had vegetables stored at 25-27°C, and 49.2% kept vegetables in market for 2-3 days.