This series of Clinical Pearls presents four cases presenting with infection. Each of these cases had clinical clues to the correct diagnosis, which could be picked up on meticulous history, clinical examination, or basic laboratory investigations. The authors highlight the important lessons to be learnt from each case. The first is a 7 year old boy with recurrent respiratory tract infections since early life. Clinical examination revealed the presence of dextrocardia and situs inversus and bronchiectasis leading to a diagnosis of Primary Ciliary Dyskinesia. The second case is a 1.5-month-old infant who presented with meningitis and increasing head size since birth. CSF examination and CT scanning led to the correct diagnosis of congenital Toxoplasmosis. The next case is an infant with high grade fever and neck swelling. He had the rare Lemierre's syndrome comprising of oro-pharyngeal infection, suppurative thrompbophlebitis of the internal jugular vein and systemic dissemination of septic emboli. The fourth case is a 2-year-old infant with recurrent respiratory tract infections and discharging neck swellings from early life. Repeated testing for tuberculosis was negative. The diagnosis was Chronic granulomatous disease. The authors describe the clinical approach and investigations in these cases; along with an outline of the management.