Head Cabbage is an important vegetable crop for food security as well as to generate income for subsistence farmers. Weeds cause yield losses of head cabbage, which is estimated to be about 25%. A field experiment was therefore conducted to determine the appropriate weeding time and frequency on head cabbage at Burie district, West Gojjam, Amhara Region under irrigation during the 2022/23 irrigation season.. Treatments consisted of weeding time at 15 day, 22 day,29 day,36 day, 15 & 22 days,15 & 29 days,15 & 36 days,22 & 29 days,22 & 36 days,29 & 36 days, 15, 22 & 29 days, 15, 22 & 36 days, 15, 29 & 36 days and22, 29 & 36 days after planting and a treatment without weeding. Treatments were laid out in RCBD design with three replications. The phenological, growth, yield related and weed parameters were collected and analyzed using SAS software (version 9.1). The analysis of variance showed that weeding frequency and time of weeding significantly influenced most of the tested parameters of head cabbage. Two times weeding at 22 and 36 days performed well in most of the tested parameters of heed cabbage, such as number of leaves per plant, head diameter, 75% head maturity, marketable yield, and total yield, compared to other tested treatments. Higher cabbage yield (11.3 t ha ) was produced on tretament that weeded two times at 22 and 36 days . Three times weeding at 22, 29, and 36 days scored low dry weed biomass and weed density. Marginal rate of return is high on (9109.9%) treatments that weeded two times of weeding at 22 and 36 days compared with other treatments. Therefore, it is concluded that head cabbage weeded two times at 22 and 36 day is critical period of time weed managment. Since this conclusion is based on a single experiment, it needs further research over location and season to give strong recommendation.