Analysis of growth performance of principal foodgrain crops in North Bihar (India) revealed that their production recorded positive growth rates during post green revolution period. Wheat was the only crop which recorded positive growth rates in area, production and productivity across the zone over different sub-periods. There has not been substantial increase in area under rice during period under investigation. Moreover, a declining trend in rice area has been observed during early nineties. The study of instability indicated that wheat, maize and arhar witnessed a continuous decline in instability over the period under study. The decline in stability in the production of these crops has been caused mainly by adoption of improved technology in crop production. The spectacular growth in production was associated with increase in instability but it started declining after the perfection in technology.