Suicide is a major public health concern. There are several risk factors associated with suicide. Chronic illnesses, such as asthma, have been linked to an increased risk of suicide-related events. This study reviews the evidence of an association between asthma and suicide using published epidemiological observational studies. An electronic search using PubMed and EMBASE was performed. Studies that investigated the association of asthma with suicide-related behaviour were selected. Studies were examined to form a descriptive analysis. Six observational studies met the selection criteria, of which at least one suicide-related adverse event was studied. Three studies investigated completed suicide, two suicide attempts and four suicide ideation. Two of the studies focused on individuals aged <18 yrs. Evidence from observational data support the hypothesis of an association between asthma and suicide-related behaviour (ideation, attempts and completion); however, epidemiological studies, with more objective measures and larger sample sizes, adjusting for a wider scope of suicide-related confounding factors (e.g. comorbidities), and with a longitudinal design, are needed for a more conclusive answer.