We report a 67 year old lady with Rheumatoid Arthritis (RA) and mild bronchiectasis (BE) whose treatment was escalated to Rituximab. Nine months after commencing Rituximab her lung sepsis worsened dramatically with repeated hospitalization, new sputum isolation of Stenotrophomonas maltophilia and Pseudomonas aeruginosa and marked radiological deterioration in BE. She was found to have a low serum IgG and IgM levels almost certainly as a complication of Rituximab. Immunoglobulin replacement therapy was instituted and her clinical status has slowly improved.