OBJECTIVE Stroke survivors live with varied degrees of disabilities and cares are provided largely by the informal caregivers. This study investigated informal caregivers' burden and strains of caring for stroke patients. METHODS This study involved 157 (81 males and 76 females) informal caregivers of stroke survivors receiving care in all secondary and tertiary health institutions with physiotherapy services in Lagos State, Nigeria. Information was collected through self-administered questionnaire during clinic-hours. Data was analyzed using Spearman's Rank Correlation Coefficient. RESULTS The patients' age ranged between 20 and 79 (mean=59.6 ± 14.6 years). Sixty-one had haemorrhagic stroke while 96 had ischaemic stroke. The informal caregivers' age was 39.2 ± 12.8 years (range: 17-36 years). More (60.8%) participants reported moderate objective while 79.2% had mild subjective burdens. The following factors significantly increased (P<0.05) the level of burden and strains experienced by the informal caregivers: closer intimacy with the stroke survivors, fewer number of caregivers for the stroke patient, longer duration since the onset of stroke and more hours of caregiving per day. Caregiving had negative significant influence (P<0.05) on the social, emotional, health and financial well-beings of the informal caregivers. CONCLUSIONS Caring for stroke survivors put social, emotional, health and financial burdens and strains on the informal caregivers. These burdens and strains increase with duration of stroke, intimacy, smaller number of caregivers and length of daily caregiving. Therefore, informal caregivers should be involved in the rehabilitation plan for stroke patients and their well-being should also be given adequate attention.