Within the KUSTOS program (Coastal Mass and Energy Fluxes-the Land-Sea Transition in the Southeastern North Sea) 28 to 36 German Bight stations were seasonally surveyed (summer 1994, spring 1995, winter 1995-1996) for light conditions, dissolved inorganic nutrient concentrations, chlorophyll a (chl a), and photosynthesis versus light intensity (P:E) parameters. Combining P:E curve characteristics with irradiance, attenuation, and chlorophyll data resulted in seasonal estimates of the spatial distribution of total primary production. These data were used for an annual estimate of the total primary production in the Bight. In winter 1996 the water throughout the German Bight was well mixed. Dissolved inorganic nutrient concentrations were relatively high (nitrogen [DIN], soluble reactive phosphorus [SRP], and silicate [Si]: 23, 1, and 10 μM, respectively). Chl a levels generally were low (< 2 μg l -1) with higher concentrations (4-16 μg l-1) in North Frisian coastal waters. Phytoplankton was limited by light. Total primary production averaged 0.2 g C m-2 d-1. Two surveys in April and May 1995 captured the buildup of a strong seasonal thermocline accompanied by the development of a typical spring diatom bloom. High nutrient levels in the mixed layer during the first survey (DIN, SRP, and Si: 46, 0.45, and 11 μM, respectively) decreased towards the second survey (DIN, SRP, and Si: 30.5, 0.12, and 1.5 μM, respectively) and average nutrient ratios shifted further towards highly unbalanced values (DIN:SRP: 136 in survey 1, 580 in survey 2; DIN:Si: 13.5 in survey 1, 96 in survey 2). Chl a ranged from 2 to 16 μg l-1 for the first survey and rose to 12-50 μg l-1 in the second survey. Phytoplankton in nearshore areas continued to be light limited during the second survey, while data from the stratified regions in the open German Bight indicates SRP and Si limitation. Total primary production ranged from 4.0 to 6.3 g C m-2 d-1. During summer 1994 a strong thermal stratification was present in the German Bight proper and shallow coastal areas showed unusually warm (up to 22°C), mixed waters. Chl a concentrations ranged from 2 to 18 μg l-1. P:E characteristics were relatively high despite the low nutrient regime (DIN, SRP, and Si: 2, 0.2, and 1.5 μM, respectively), resulting in overall high total primary production values with an average of 7.7 g C m-2 d-1. Based on the seasonal primary production estimates of the described surveys a budget calculation yielded a total annual production of 430 g C m-2 yr -1 for the German Bight. © 2006 Estuarine Research Federation.