The available data on the terrestrial influx of small meteoric particles (mass<1 gram) are surveyed. Whereas, in the past, flux determinations differed by factors of as much as 100 million, it is shown that recent experimental data are far more consistent, variations being limited to a factor of 10 for particles of mass greater than 10−10gram. The sensors from which the data are obtained are discussed, with particular emphasis on those used in situ, and inherent uncertainties in the results are pointed out. A best estimate of the cumulative mass distribution influx is given on the basis of the most recent data available. This estimate uses the NASA Meteoroid Environment Model, 1969. Uncertainty limits due to differing experimental results and interpretations are placed upon this flux model. For masses larger than about 10−10gram, the uncertainty is less than 1 order of magnitude; whereas for smaller particles the uncertainty may still be as large as 4 or 5 orders of magnitude. The present best estimate of the mean density of the small meteoric particles is 0.5 g/cm³, but there are indications that several classes of meteoroids exist with densities ranging from 0.3 to 1.2 g