This cross sectional study was carried out in Dhamar governorate from December 2015 to November, 2016 with main objective to determine the seroprevalence of toxoplasmosis in humans and animals. A total of 323 individuals and 323 animals (241 sheep, 69 cattle and 13 goats) from different districts of Dhamar governorate were selected and tested using ELISA and PCR techniques for detection antibodies against Toxoplasma gondii in human and animals. The results revealed that, the overall seroprevalence of toxoplasmosis in human was 20.43%. The seroprevalence rates of IgG, IgM and both IgG +IgM were 13.62%, 4.33% and 2.48% respectively. The higher rate of infection was recorded (29.50 %) in age group of 11-20years old; whereas, the lower rate (11.11%) was in age group of less than 10 years old. Females were more susceptible to infection (23.19 %) compared to males (2.02 %). The higher seroprevalence rate was recorded in summer (28.41%); whereas, the lower rate in spring (13.15%). The higher prevalence of rate was recorded in Utoma district (32.00%); whereas, lower rate in Alhada district (3.85%). Statistically, significant differences (P<0.05) were observed between seroprevalence rate and age group, sex; while none with season and area factors. In animals, the results of ELIZA revealed that, the overall seroprevalence of toxoplasmosis was 23.84 percent, the seroprevalence of IgG, IgM and both IgG +IgM were 15.5%, 1.5% and 6.8% respectively. Out of 241 sheep, 69 cattle and 13 goats tested, 21.16%, 31.88%, 30.77% respectively were seropositive for toxoplasmosis. The infection rate of toxoplasmosis was high in age group of 5 years old and above (33.33%); whereas, low (21.55%) in age group of two years. The seroprevalence rate in males was (28.28%) higher compared to females (21.88 %). The higher seroprevalence rate was recorded in spring season (33.33%); whereas, the lower rate in winter (18.02.67%). The higher of seroprevalence was recorded in Utoma (35.71%); whereas, the lower rate in Mifa`a ans (10.715%) and none in Jabal asharq. Statistically, significant differences (P<0.05) were observed between seroprevalence rate and animal species, season, area factors; while, none with other factors studied. In the present study, all ELISA seropositive samples of human and animals were retested by PCR as confirmatory tool. Results of PCR revealed that, out of 66 and 77 samples of human and animals tested 30 (45.45%) and 18 (23.38%) were found positive respectively for toxoplasmosis. The results of the present study revealed that toxoplasmosis is prevalent in human and animals in study area. Combinations of serological and molecular techniques are recommended for accurate diagnosis of Toxoplasmosis.