Acute pancreatitis (AP) is an unpredictable disease accounting for more than 50% of all hospital admissions for pancreatic diseases. The disease is generally mild and self-limiting, but about 20% of the patients develop moderate to severe AP with poor prognosis leading to high morbidity and mortality. Recently increased occurrence of AP has been noted with severe AP requiring several weeks to months for treatment. Acute pancreatitis may get complicated by pancreatic and/or peripancreatic necrosis, which may become infected through several routes. The pathogenesis of secondary bacterial pancreatic infection is still under controversy. Acute pancreatitis is the setting for most infections of the pancreas, which can complicate various stages of pancreatitis. In some patients, AP develops into necrotizing pancreatitis. Patients with AP-related infected pancreatic necrosis (IPN) are prone to develop organ failure, leading to increased mortality, further complicated by multidrug-resistant (MDR) microorganisms. The bacterial spectrum in IPN reflects the commensal flora of the intestine. Clinically, there are no reliable parameters to distinguish infected from sterile necrosis as the clinical features are indistinguishable from other infectious conditions. Infected pancreatic necrosis can be diagnosed mainly by laboratory methods like culture and radiographic scan. The management of AP has developed considerably during the past decades. The preferred choices are primary conservative and minimally invasive modalities compared to open surgical necrosectomy. Antibiotics are generally not given to patients with severe AP because of limited clinical benefits. Various aspects of infections of AP inclusive of diagnostic and management modalities have been reviewed here.