A field investigation was carried out during winter season of 2011-12 and 2012-13 at IARI Regional Station, Karnal (Haryana) to evaluate the effect of pre and post emergence herbicides on weeds, seed yield and seed quality of garden pea cv. Pusa Pragati. The twelve treatments viz. imazethapyr 50, 75 and 100g ha-1 (20DAS), pendimethalin 0.75 and 1.50kg ha-1 (pre-emergence), trifluralin 1.00 and 1.50kg ha-1 (PPI), ready mixture of imazethapyr and imazamox 50, 70 and 90g ha-1 (20DAS), hand weeding twice (20 and 45 DAS) and unweeded check were tested in randomized block design with three replications. The treatments hand weeding twice and imazethapyr @ 75g and 100g ha-1 recorded significantly higher pods per plant, seeds per pod, pod filling, 100 seed weight and seed yield than other herbicidal treatments and unweedy check. These treatments also recorded lower weed dry weight and higher weed control efficiency than other treatments. It may be inferred from the present investigation that in addition to hand weeding twice, post emergence herbicide imazethapyr @ 75g ha-1 (20DAS) can be used effectively as an alternative for controlling weeds and in obtaining optimum seed yield and quality in garden pea under Karnal (Haryana) conditions.