The theological and transport properties of highly concentrated inverse phase (water-in-oil, w/o) emulsions were studied. The concentration of the aqueous (disperse) phase was 94%. The flow curve of fresh emulsion is described by the Cross equation. Aging leads to changes in the rheological behavior of the emulsion: the Newtonian flow domain disappears, the apparent viscosity increases and typical yielding is observed. The flow curve of this "aged" emulsion is described by the Hershel-Bulkley equation. Preliminary deformations lead to a slight dilatant effect. Shearing the emulsion through a transition stress threshold of approximately 300Pa leads to radical changes in the theological behavior, including loss of stability in tube flow. Stable invert, highly concentrated emulsions have elastic moduli that do not depend on stress and are not affected by transition through the yield limit. Their storage modulus is stable with respect to the deformation amplitude up to 10% strain, while the loss modulus is very sensitive to deformation amplitude. The theological properties of samples taken from a pipeline are close to the properties of "aged" samples. Experimental data obtained in a rheometer can be used successfully for the prediction of the transport characteristics of the emulsion in pipelines for pipes of large diameter. The choice of the flow curve parameters is not crucial for the results of calculations of transport characteristics of the emulsion. (C) 2003 Published by Elsevier Science B.V.