Skin sympathetic reflexes need to be recorded from more than one site over the hand and foot if the quantitative measure is to be of significance. For this purpose the instrument must to be sensitive enough to detect variations of a fractional of a percent of skin impedance. Method: To support sympathetic investigation we have developed a system which combine the functionality of a battery of tests with the flexibility of a computer analysis environment based on a dual-channel self-balancing impedance reactometer. Measurement of skin sympathetic reflexes in 33 healthy subjects, aged under 50 yrs. was performed by noninvasive monitoring transient change in the skin impedance both in phase (resistive) and in quadrature (capacitive) on rest and after a stimulus. The procedure requires a placement of a pair of surface electrodes on the skin and application upon the subject an endogenous/ exogenous stimulus. 12 bit data resolution specially designed data acquisition card is used which converts the signals into digital form and transfers this to the computer IBM PC XT/AT data bus directly. The software developed for the system written in Pascal, displays the data on standard PC colour monitor in real time 1, 2 or 4 traces at a time. Results: An autonomic response is an extremely complex state of the subject and can be characterized by many parameters which may have both temporal and spatial dependencies. The sympathetic response signal to be recorded is superimposed on a background signal which may be orders of magnitude larger but constant during the recording time. The insertion of the self-balancing circuit into the detection electronics, the background signal is compensated, the sympathetic signal is not affected and could be detected with the highest sensitivity. Transient skin sympathetic response was 2.18 +/- 0.31 %/s at hand, 1.41 +/- 0.42 %/s at foot and 0.27 +/- 0.14 %/s in other site of the body. The potential of the system is currently investigated for on line diabetic foot analysis.