Hypersensitivity reactions (HSRs) to platinum drugs are increasing due to their extensive use in a wide variety of malignancies and the repeated exposures in patients with increased life expectancy. Understanding the incidence of HSR to platinum drugs and associated risk factors can help with the diagnosis and may provide protection against severe HSRs. A thorough clinical history with identification of the typical and atypical symptoms, the relationship with the platin administration, and the number of previous exposures are the key to the diagnosis. An elevated serum tryptase at the time of the HSR indicates that IgE and/or mast cells/basophils were involved in the HSR. Skin testing to platinum drugs is a highly sensitive and specific diagnostic tool, which helps provide risk stratification and management recommendations. Platinum specific IgE measurement and basophil activation test (BAT) are emerging as new diagnostic tools and in combination with skin testing can help support the diagnosis and the cross-reactivity between the three most commonly used platinum drugs, namely carboplatin, cisplatin, and oxaliplatin.