In order to study the response of plasma prolactin (PRL) to acute psychological stress and to compare it with that of growth hormone (GH), the mirror drawing test (MDT) was performed in 20 normal controls (11 male, 9 female) and 22 neurotic patients (12 male, 10 female). Plasma PRL and GH were measured serially before, during and after the test. In controls, the test caused no significant change in plasma levels of either hormone. In neurotic males, the response of PRL to the test was not consistent, whereas, in neurotic females, plasma PRL level rose significantly following the test. Increase of GH, on the other hand, was apparent in the neurotics of both sexes. The correlation between the responses of the two hormones in the neurotics was low and non-significant. The results indicate that although the psychoendocrine coping mechanism in the neurotics works less effectively for both PRL and GH, the two hormones may have different psychological correlates.