Knowledge on the nature and magnitude of genetic diversity is the primary requirement for the initiation of breeding programs. Therefore, the present experiment was conducted to assess the genetic diversity and association of traits among 81 field pea (Pisum sativum L.) accessions using simple lattice design at Kudmi Kebele, Mecha District, Northwestern Ethiopia in 2020. Data were taken on 5 qualitative and 13 quantitative traits. Analysis of variance showed highly significant variation for days to flowering, seed-filling period, days to maturity, plant height, number of primary branches per plant, number of pods per plant, number of seeds per pod, pod length, pod width, hundred seed weight, biomass yield, harvest index and seed yield, indicated the presence of considerable variations among the tested field pea accessions which helps for improving the yield of field pea through selection. PCV was slightly higher than GCV for most of the studied traits, indicating the minimal influence of the environmental factors. Higher heritability was recorded for days to flowering, days to maturity, plant height, number of pods per plant, pod width, hundred seed weight, grain yield and biomass yield which aids for selection of individuals based on phenotypic expression. High genetic advance was obtained for seed yield, biomass yield, harvest index, number of pods per plant, pod width and hundred seed weight which improves the possibility of selection based on these traits. A higher magnitude of genotypic correlation than phenotypic correlations suggests the presence of an inherent relationship between the studied traits and environment. Seed-filling period, hundred seed weight, biomass yield and harvest index were traits of field pea which exert positive direct influence on grain yield which helps for improving grain yield indirectly. The 81 field pea accessions were grouped into 7 clusters which showed the availability of substantial genetic diversity. 5 principal components accounted for 73 % of the total variation among the tested accessions. The result showed the presence of variability among the tested accessions.