Hereditary spastic paraplegia (HSP) or Strümpell-Lorrain syndrome is a heterogeneous group of inherited disorders, with prevalence ranged from 4.3 to 9.6 cases per 100,000 population. A common feature of these disorders is the slowly progressive and often severe spasticity, noticeably especially in the low limbs. Conventionally, HSP is divided into two clinical groups, uncomplicated (pure spastic paraplegia) or complicated HSP depending on the presence of other neurological features in addition to spastic paraparesis. Inheritance may be autosomal dominant, autosomal recessive or rarely X-linked, but autosomal dominant inheritance is most commonly associated with pure forms of the disease, whereas autosomal recessive HSP shows greater phenotypic variability, including several well-defined syndromes. Genetic studies have revealed as many as 31 different chromosomal HSP loci. We investigated two subjects, brother and sister, who were diagnosed using the criteria for a diagnosis of HSP proposed by Fink (1996), as "definitely affected" with HSP. As some particularities, we noticed an iliopsoas pseudohypertrophy in male patient and a mild atrophy in female, maybe due to degeneration of anterior columns. Family history recorded the presence of same manifestations in relatives. The pedigree of patients revealed some anomalies that could be related with the pathology. Our findings supported the diagnosis of complicated form of HSP in both cases.