Spontaneous subarachnoid haemorrhage accounts for 5% of strokes and it usually affects healthy and active people. It is most often caused by a rupture of an intracranial aneurysm and it bears a great burden of death and further complications, i.e. cerebral vasospasm and hydrocephalus, both of which still pose a great diagnostic and therapeutic challenge for physicians. Management of patients after aneurysmal subarachnoid haemorrhage largely consists of monitoring and prevention of a secondary injury. While some promising modalities of neuromonitoring have not been universally acknowledged yet, novel and less invasive strategies are studied. Metabolomics, which is one of them, is an analysis of all or at least of a large number of small molecule metabolites in a biological sample at one time. Herein we present a systematic literature review on metabolic changes after aneurysmal subarachnoid haemorrhage, with particular emphasis on concentration of excitatory amino acids and free fatty acids in cerebrospinal fluid. Although the literature review demonstrates limited knowledge in this field, it seems to be a beneficial direction for further research. Small molecule metabolites carry out important physiological functions which, however, may convert to deleterious effects under pathological conditions. As they are ubiquitous across the body, they constitute an ideal target for biomarker research.