Weeds are one of the major limiting factors for economically viable celery production. Agrochemicals are useful for control of weeds and their benefits may be estimated in terms of reduced crop losses. This study was conducted to analyse the farm-level economics of agrochemical use for weeds in celery grown in Izmir, Turkey. Data were collected from 24 farmers using a random sampling method. According to the results of the study, the treatment index of agrochemicals used for weed control varied between 0.48 and 1.60. The number of farmers who used a lot of agrochemicals for weeds was 9 (38%). The average usage of agrochemicals per hectare (as active ingredient) for weeds and all pests in celery production was estimated to be 1.76 and 1.90 kg/ha, respectively. The average agrochemical use and application cost was determined as $111/ha. Agrochemicals and their application costs formed 3.79% of variable costs and 2.90% of total costs, respectively. The share of the costs of weed control in total agrochemical costs for pests was 40.29%. (C) 2007 Elsevier Ltd. All rights reserved.