Brassica oleracea variety “italica” (broccoli) is a commercially important vegetable crop within the Brassicaceae family since it has been cultivated for over two millennia after originating from the Mediterranean region. Broccoli furthers sustainable agriculture beyond economic and nutritional importance, and glucosinolates in broccoli improve soil fertility and likewise stimulate helpful microbial activity furthermore provide natural pest regulation. Regardless of its numerous merits, biotic stressors severely constrain its production because downy mildew, club root, fusarium wilt, and turnip mosaic virus do collectively cause substantial yield losses. This chapter takes a look in depth at the disease cycles of major pathogens, it analyzes all of the dynamics of host pathogen interactions, and it explores each of the underlying genetic mechanisms of resistance. Particular emphasis goes toward resistant cultivars’ development and performance. Rapid evolution of the pathogen population generates innate challenges, specifically in pathotype-specific and broad-spectrum cultivars that compromise resistance durability. Furthermore, the chapter explores the application of biotechnological strategies (expression of cry genes in plants for pest resistance), while it addresses the emerging issue of pest tolerance to interventions. Also highlighted is the changing role of genomic databases like BRAD, ensemble plants, NGDC, plant garden in resistance gene discovery, synteny analysis, comparative genomics, and molecular marker development. Along with next-generation sequencing as well as advanced analytical tools, these resources have substantially strengthened broccoli breeding programs so that these programs can precisely target genetic improvements. This work outlines a thorough framework for improving resilience of broccoli against biotic stresses and securing its role in advancing sustainable agriculture since conventional breeding, genomic technologies, and management practices become integrated.