Bangladesh suffered the century's worst flood during July-October 1998 and appealed for assistance. To provide information for appropriate interventions to tackle nutritional problems, a rapid assessment survey was conducted to look at the nutritional situation, problems encountered by the community, their coping mechanisms and rehabilitation priorities in six rural areas. The survey was repeated after four months to measure the outcome of activities during the flood and the necessity for future assistance. There were 3,048 children measured in both surveys (1,597 and 1,451). The sample of most interest was a sub-group of 180 children present in two previous independent surveys. The analysis found that while moving from the crisis period to post-flood phase there was evidence of a 'crossover phenomenon' in the recovery pattern of nutritional status. Sixty-eight per cent of the children who were malnourished (WHZ < -2SD) during the crisis period (18 per cent) recovered enough to cross the cut-off point and became normal after four months. Another 8 per cent of children (9 per cent of all normal) who were normal during the crisis period, after four months had deteriorated to be malnourished. Thus, despite there being a shift in the overall distribution of nutritional status, there has been another shift that reduced the net effect. Subsequent episodes of diarrhoea, access to food and loan burden had also influenced the recovery pattern of the children's nutritional status as evident from the statistically significant associations. These findings raise questions about targeting acute malnutrition during emergencies, and using the same criteria during both the crisis and rehabilitation phases.