Sparfloxacin is an antibiotic in the quinolone group of antibacterial agents, which often induce photosensitive skin reactions, more often phototoxic reactions than photoallergic ones, and sometimes associated photo-onycholysis. We present a case of phototoxic dermatitis with photo-onycholysis in a 38-year-old man probably induced by sparfloxacin, which was prescribed to him along with rifampicin and clofazimine because he was suffering from borderline lepromatous leprosy. He developed exaggerated sunburn-like eruptions mainly on sun-exposed sites along with painful onycholysis of the fingernails. Interestingly, the hypopigmented patches of leprosy were spared, which is a very rare phenomenon. Withdrawal of sparfloxacin along with administration of systemic steroids and other supportive measures helped heal the skin eruptions with hyperpigmentation, but the photo-onycholysis was slow to resolve.