The properties of the inversion recovery (IR) sequence are considered and its use in clinical practice is illustrated. The effect of changing repetition time, inversion time (TI), and echo time; the method of data encoding; the type of data collection; and the method of image processing are analysed. Normal appearances and clinical examples in the central nervous system and the remainder of the body are used to illustrate the many options available with this sequence. The short TI IR sequence has advantages in magnetic resonance imaging of the body, and medium TI sequences are of value in localisation in the brain and in demonstrating contrast enhancement. Long TI sequences can be used in pediatrics and for separating tumour and oedema. Suppression or partial suppression of fat and fluid signals are two useful options with IR sequences.