Anorexia nervosa (AN) is a psychiatric disorder that may lead to cardiac complications. The objective of this study was to evaluate global and regional longitudinal strain changes in patients affected by AN as an early marker of myocardial damage. We prospectively enrolled 48 consecutive patients with AN and 44 age-matched and gender-matched healthy controls. In all subjects, we performed echocardiography, including global longitudinal strain (GLS) measurement. A subset of 33 patients with AN had further echocardiographic examinations during the follow-up. Compared with healthy controls, patients with AN had a greater prevalence of pericardial effusion (9 of 48 vs 0 of 44, p = 0.003), a smaller left ventricular mass (63 ± 15 vs 99 ± 30 g, p < 0.001), a lower absolute value of GLS (-18.9 ± 2.8 vs -20.2 ± 1.8%, p = 0.010) and of basal LS (-15.4 ± 6.0 vs -19.4 ± 2.6%, p < 0.001). The bull's eye mapping showed a plot pattern with blue basal areas in 18 of 48 patients with AN versus 1 of 44 controls (p < 0.001). During the follow-up, of 13 patients with blue areas in the first bull's eye mapping, 11 recovered completely, and of 20 patients with a red bull's eye at the first examination, none presented blue areas at the second one. In conclusion, GLS is significantly altered in patients with AN, and a basal blue pattern on bull's eye mapping identifies more severe cases. These changes seem to be reversible.