Nine days into filming, Ebsen started to experience shortness of breath and cramping that sent him to the hospital. At one point his lungs failed. He remained hospitalized for two weeks, during which time the film's producer hired actor Jake Haley to play the Tin Man. Haley's makeup was reformulated into a paste that was painted on. He missed four days of filming when the makeup caused an eye infection, but he did not suffer any permanent damage and did not lose his job.
Ebsen's recording of "We're Off to See the Wizard" with Dorothy, the Scarecrow and the Cowardly Lion, was used in the film's soundtrack.