This paper is concerned with the optimum interpolation of sampled data when various types of jitter are present. The two basic types of jitter are the departures from intended sampling times in taking the data (read in jitter) and the misplacement of the sample pulses from the intended times when they enter the interpolation filter (read out jitter) . In some applications the two jitters are equal and this is termed locked jitter. Arbitrary jitter spectra are considered and specific results are obtained for high and low frequency spectra present with read in, read out, and locked jitter. The following are some of the observations made: locked jitter generally introduces less error than read in or read out jitter (when the jitters all have the same statistics) ; in the limit of low frequency jitter, read in and read out jitter introduces the same error and locked jitter introduces no error; if the spectral spread of the jitters go to infinity with the sampling period maintained adequate, the various mean s...