The conditions for the cultivation of the 229-E respiratory virus in tissue culture are described. The virus multiplies only in human tissue culture systems, but a variety of cell types are sensitive to it. The virus has been isolated in three continuous cell lines and a plaque assay has been developed in one of these. This cell line (L 132) derived from human embryo lung, was also used to isolate three other viruses of similar morphology which had previously been cultivated only in organ cultures of human respiratory epithelium. High rates of isolation of these viruses were made in L 132 cells using nasal washings from experimentally inoculated volunteers. It is concluded that this cell line is a valuable tool in the study of viruses of this group.