The number of recognized causes of inherited thrombocytopenias has grown in the past 10 years and there are now more than 18 thrombocytopenic disorders with characterized genetic mutations. Moreover, the pathogenic mechanisms of many forms of inherited thrombocytopenia have been identified and prognosis of different disorders, ranging from unfavorable to very good, has been defined. In addition, for some inherited thrombocytopenias, therapies are now available to improve both survival and quality of life for persons with these conditions. Therefore, it is important to recognize when a low platelet count reflects an inherited disorder, and establish a correct diagnosis; however, this remains a challenge because documented evidences about these diseases are scarce. In this review, we address how to diagnose inherited thrombocytopenia, how to differentiate these conditions from immune thrombocytopenia, present a new and simple diagnostic algorithm, and discuss the different therapeutic options. We also emphasize that further research on these disorders is needed, as about half of patients with inherited thrombocytopenias have a disease that is not yet characterized.