In February 1954 while doing his teaching at Harvard, Lashley unexpectedly collapsed and was hospitalized. He was later diagnosed with Hemolytic anemia and was put on aCortisone treatment. The Cortisone eventually began to soften his vertebrae, and as a result a Splenectomy was performed. He was on the road to a full recovery until his trip to France with his wife Clair, where he once again unexpectedly collapsed, but this time to his death on August 7, 1958.[2]