A field experiment was conducted to identify better performing improved linseed cultivar and to determine the optimal weeding frequency in 2018-2019 main cropping season. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The treatments were factorial combination of four weeding frequencies (weedy check, once weeding, twice weeding and thrice weeding) and four improved linseed cultivars (Kuma, Yadano, Kulumsa-1, and Kasa-2) and one local check. Results showed that number of primary and secondary branches per plant, number of capsules per plant, biological yield, seed yield, straw yield, and harvest index were significantly affected by the main effect of weeding frequency and cultivars. While number of tillers per plant, number of seed per capsule, thousand seed weight and oil content were significantly affected by the interaction effect of weeding frequency and cultivars. Significantly higher seed yield (1175.5kg ha-1) was obtained from Kuma linseed cultivar, while the lower seed yield (532.5kg ha-1) was obtained from local check. Thrice and twice weeded treatments produced significantly (P<0.01) higher seed yield (1259.4kg ha-1 and 1197.8 kg ha-1 respectively), which were not statistically different, while the lowest yield (512.8kg ha-1) was obtained from weedy check. Results showed that 59% yield loss was observed among treatments when weeds were allowed to grow for the whole season. Significantly (P<0.01) higher (39.1%) oil content was recorded from the interaction effect of three times weeded Kuma cultivar, while the lowest oil content (34.1%) was recorded from weedy check with local check. Cost benefit analysis indicated that the maximum net profit (ETB 26099.8 ha-1) with marginal rate of return (147.4 %) was obtained from two times weeding. Hence Kuma cultivar and two times hand weeding which can be recommended to increase production of linseed at Guder, and areas with similar agro-ecologies.