We previously reported that expression of retinoic acid receptor β increases in the sclera of the 2-week-old chick with form deprivation myopia (FDM) and that all- trans-retinoic acid ( t-RA) influences proliferation and differentiation of scleral cells. The purpose of this study was to quantify t-RA in the retina of the chick with FDM and to investigate the role of t-RA in FDM in the chick. FDM was induced in 2-day-old chicks by placement of a translucent plastic goggle over one eye, with the contralateral eye used as a control. After 5 days, the chicks were sacrificed. t-RA was extracted from neural retina and served for high-performance liquid chromatography analysis. <sup>3</sup>H- t-RA was used for normalization. Pieces of the retinae from 5 eyes served as one sample. As a result, t-RA was 0.960 ± 0.086 ng/eye (0.387 ± 0.056 ng/mg protein) in the myopic retina and 0.864 ± 0.108 ng/eye (0.319 ± 0.043 ng/mg protein) in the control retina. The concentration of t-RA (ng/mg protein) in the myopic retina was significantly higher than that in the control (p < 0.05, n = 7). These results demonstrate that t-RA increases in the retina within 5 days after visual deprivation. This finding suggests that t-RA may play a role in the metabolic changes in FDM.