Plasmodium parasites replicate asexually in the human host, and, in each replication cycle, a portion of the asexual stages develops into sexual gametocytes. The proportion of infections that carries gametocytes is a proxy for human-to-mosquito transmissibility. The documentation of P. vivax infections in Africa where the predominant population is Duffy-negative demonstrates the ability of P. vivax to replicate asexually in Duffy-negative hosts, causing malaria symptoms. However, it is unclear what proportion of P. vivax infections in Duffy-negatives carries gametocytes. This study aims to determine the prevalence of P. vivax in Duffy-negatives across broad regions of Ethiopia and characterize parasite stages including gametocytes among P. vivax infections. Of the 447 P. vivax confirmed samples collected from southwestern, northwestern, and eastern regions of Ethiopia, 17 were from Duffy-negatives with the highest number observed in the Amhara and Oromia. Among them, five (29.4%) were detected with gametocytes. There were 348 cases that were Duffy positives and 162 (46.5%) of them were detected with gametocytes, much higher than that in Duffy-negatives. A wide range of difference in parasitemia is observed among P. vivax samples in Duffy-negative individuals. A few infections in Amhara (north) and Oromia (southwestern) show high parasitemia comparable to Duffy-positives. In Oromia, mixed rings and trophozoites were most common in the P. vivax cases. This finding is the first to report the presence of gametocytes in P. vivax from Duffy-negatives, suggestive of human-to-mosquito transmissibility. Although P. vivax infections in Duffy negatives are commonly associated with low parasitemia, these infections may represent hidden reservoirs that might contribute to transmission. A better understanding of P. vivax transmission biology and gametocyte function particularly in Duffy-negative populations would aid future treatment and management of vivax malaria in Africa.