Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease characterized by the selective death of lower motor neurons in the anterior horns of spinal cord. SMA is caused by mutations in the survival motor neuron 1 gene (SMN1), leading to the reduced expression of the full-length SMN protein that protects the motoneurons in the anterior horns of the spinal cord from apoptosis. The survivance of motoneurons depends beside others on motoneuron specific microRNAs (miRNAs), which control their normal development, differentiation, axonal growths, synaptogenesis and apoptosis. The main role of miRNAs is regulation of post-transcriptional gene expression. Motor neuron-specific miRNAs dysregulation in SMA might be implicated in their selective vulnerability. The detection of these miRNAs in cerebrospinal fluid and/or blood plasma might lead to the discovery of biomarkers and early diagnostics of SMA, prediction of the severity and of progression speed of the disease and monitoring of the treatment.