Broccoli is a vegetable of high nutritional value, rich in bioactive compounds, but has a fast degradation after harvest. This work assesses the effect of hyperbaric pressure, at room temperature, on postharvest conservation of broccoli. The broccoli samples were subjected to the five hyperbaric pressures (100 control, 200, 400, 600, and 800 kPa) during three different times (1, 2, and 3 days), at 22 °C and 95% RH. The pressures of 400, 600, and 800 kPa provided the best conservation of broccoli quality. Respiratory rate, ethylene production, soluble solids content, and lipid peroxidation decreased at the highest-pressure treatments. Moreover, the highest pressures maintained fresh mass, green color, ascorbic acid content, and receptacle firmness. The hyperbaric treatments of 600 and 800 kPa increased catalase enzymatic activity and reduced peroxidase activity as a result of the reduction of oxidative stress, delaying the senescence of broccoli.