Abstract
Cefotaxime is a third generation cephalosporin with good coverage against gram negative organisms. Anaphylaxis is a commonly reported adverse effect. This is a case of a middle aged lady who presented with fatigue and was diagnosed to have pancytopenia due to vitamin B12 deficiency. She had an associated urinary tract infection. Cefotaxime was started for the infection, following which she developed severe thrombocytopenia. Drug induced thrombocytopenia is an unpublicized adverse effect of cefotaxime.