While reviewing present status of mastitis in India, results of investigations from periurban dairy farms on epidemiological, clinical manifestations, diagnosis, bacterial isolation, in vitro drug sensitivity, and treatment of subclinical mastitis have been presented. Mastitis, on account of its causing serious wastage and undesirable milk quality, is emerging as a major challenge among the others (like breeding improvement, nutrition management, control of infectious, tick-borne, blood, and internal parasitic diseases) in dairy development of tropics. Subclinical mastitis was found more important in India (varying from 10-50% in cows and 5-20% in buffaloes) than clinical mastitis (1-10%). The incidence was highest in Purebred Holsteins and Jerseys and lowest in local cattle and buffaloes. An investigation on 250 animals from periurban farms indicated that the monsoon season was more prone to subclinical mastitis than summer or winter, prevalence increased with higher lactation number and animals in 4th-5th month of lactation were found more susceptible (59.49%), hind quarters were found more affected (56.52%) than fore quarters (43.47%). The factors like herd size, agro climatic conditions of the region, variations in sociocultural practices, milk marketing, literacy level of the animal owner, system of feeding, and management were found important affecting the incidence of subclinical mastitis. Comparison of efficacy of different diagnostic techniques for subclinical mastitis, such as modified California mastitis test (MCMT), bromo thymol blue (BTB), modified whiteside test, trypsin inhibition test, milk pH, and electric conductivity indicated MCMT to be most sensitive (95.16%) and specific (98.02%) test. The antimicrobial susceptibility test revealed that most of the bacterial strains (gram positive, gram negative, and mixed) isolated from subclinical mastitis milk samples, were highly sensitive to enrofloxacin 53.91%, least sensitive to oxytetracycline 17.39% and ampicillin 7.83%, and resistant to streptomycin. The therapy with enrofloxacin and nimesulide was found more efficacious (92.30%) in treating subclinical mastitis cows. It was concluded that consideration of socioecological factors for mastitis control in periurban area would help to reduce the cost of mastitis control in clean milk production.