Achieving sustainable development is a major challenge, especially among developing fishing nations which depend more on fisheries resources as a source of food and income. In Namibia, a developing fishing nation, many marine fishery resources were overfished pre-independence. Thus, measures implemented post-independence were aimed at sustainable utilization of fishery resources. This paper gives a sustainability analysis of the Namibian marine fishing subsector using broad aspects of sustainable development such as ecological, socioeconomic , and technological aspect. Each aspect is represented by the following indicators: Mean Trophic Levels of landings, value of landings, contribution to state revenues and Gross Domestic Product as well as type of fishing gear. Indicators were computed using secondary data obtained from the Ministry of Fisheries for the period, 1990-2007. Trends of the ecological indicator suggest an improvement in ecosystem state, which could have led to increasing value of landings and contribution to GDP. Generally, indicators used showed that fishing impacts on the ecosystem state are less and economic performance of the sub-sector was good; especially notable is the increasing number of vessels in the hake fishery relative to increase in landings. While there are signs, it is difficult to conclude with absolute certainty whether the development of the Namibian marine fishing sub-sector was sustainable.