Trends in mean length and maturity stage of Patagonian toothfish (Dissostichus eleginoides) were examined using data from approximately 7000 fish sampled by observers from the 1998 fishery around South Georgia and Shag Rocks (Subarea 48.3). D. eleginoides were distributed down the shelf slope with an approximately linear relationship existing between depth and fish length. A statistically significant pattern of changing mean length at depth with month was detected, suggesting movement of animals both up and down slope at particular times of year. Months with a high mean length at depth are May and August, and with a low mean length at depth - April and July. Examination of maturity data suggests that in addition to a major spawning event in late July/August, there may be a small spawning event in April/May. Detailed examination of maturity-at-depth data suggests that mature males move down slope and females move up slope to meet at breeding areas defined by slope position (between 800 and 1200 m depth) and not by geographical position. Pre-spawning animals appear to be distributed all around the South Georgia and Shag Rocks shelf slopes. Spent animals of both sexes appear to move up slope to shallower water, and are concentrated to the northeast of Shag Rocks. Few spent fish were found around South Georgia. This concentration of large post-spawning fish may have some implications for the management of the fishery.