Sickle cell anaemia (SCA), a common haematologic genetic condition in which an individual inherits two haemoglobin S genes from both parents, is an important cause of morbidity and mortality among children in Nigeria. The principal causes of death in SCA patients are anaemic crises and infections. The coexistence of other morbidities with anaemic crises, mainly infections, may result in adverse outcomes, even after addressing the anaemic crises; hence the need for identification of the associated morbidities of anaemic crises and institution of prompt treatment. The aim of the study was to determine the pattern of anaemic crises (the frequency of the various types of anaemic crises), their associated morbidities, the age group at greatest risk of anaemic crises, and the short-term outcome at discharge of patients with anaemic crises. Sickle cell anaemia patients aged 16 years and below, presenting with anaemic crises, defined as packed cell volume (PCV) <15% were recruited consecutively into the study. Their clinical and haematological parameters and results of other laboratory investigations, as indicated by individual patients’ clinical conditions were documented. The anaemic crises were classified, according to types, into hyperhaemolytic, aplastic, and sequestration crises; and the mixed forms which included aplastic-hyperhaemolytic, aplastic-sequestration, and recovery-phase-of-aplastic crises. Hyperhaemolytic crisis was the commonest type of crises encountered, with a frequency of 35%. There was significant (P = 0.019) association between age and type of anaemic crises; with acute splenic sequestration crisis being commoner in the under-fives, and hyperhaemolytic crisis in the older children (10 < 15yrs old). The commonest associated morbidity of anaemic crises was malaria (64%), followed by respiratory tract infection (30%). The age group with the highest frequency of anaemic crises was the 10 < 15 year olds; this being a deviation from previous observation that the frequency of both vaso-occlusuve and anaemic crises decreased with increasing age. There was significant (P < 0.0001) association between the severity of anaemia and type of crises, as patients with “mixed crises” had lower PCV than the other crises types. The finding of blood-borne infection like hepatitis B virus infection in 2% of the subjects underscores the need for routine screening of all SCA patients at enrolment for such infections, and offering immunization and treatment where applicable. The short term outcome for patients with anaemic crises was uniformly good, as no mortality was recorded. Almost all the cases studied were already diagnosed of SCA, and nearly half of them, at between the ages of 6 to 12 months, which is the usual time of manifestation of the disease.