Sickle-cell disease is a group of blood disorders typically inherited from parents. The most common type is known as sickle-cell anaemia . It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells , this leads to a rigid, sickle-like shape. Problems in sickle cell anaemia typically begin around 5 to 6 months of age. A number of health problems may develop, such as sickle-cell crisis, anaemia, bacterial infections. Long term pain may develop as people get older. The purpose of the study was to assess the pre test and post test knowledge regarding sickle cell anaemia among mothers of under five children and to evaluate the effectiveness of structured teaching programme regarding sickle cell anaemia among mothers of under five children . The study methodology was Evaluative research approach and pre experimental one group pre- test post -test design was used. Non randomized purposive sampling technique was used to select the sample of the study. The total study sample consisted of 30 mothers of under five children. The result of the study concluded that the comparison of mean, standard deviation of pre-test and post-test knowledge and paired ‘t’ test value regarding sickle cell anaemia. The pre test knowledge score is 3.73 and post test score is 9.87 and the obtained t value is 12.77 statistically significant at 0.001***. The study concluded that structured teaching programme improves the level of knowledge regarding sickle cell anaemia among mothers of under five children.