This study compares and contrasts recent and contemporary nuptiality among Maasai men of Kenya and Tanzania, and represents the first cross-national comparable data set on Maasai marriage. A variety of methodologies are used, including an individual questionnaire (n=2,394 men aged 20 and above), a survey of ethnographic evidence, and participant observation. By comparing nuptiality between Kenyan and Tanzanian Maasai, this study examines marriage among the Maasai in particular and rural sub-Saharan African populations undergoing socio-economic change in general. Maasai men marry later, on average, than the national average in both Kenya and Tanzania, and the age at first marriage appears to be declining. Relative to national levels, polygynous marriages account for a significantly higher proportion of Maasai marriages. Country-level differences in entry into and typeof (monogamous or polygynous) marriage are described and explanations sought. The Maasai ofKenya and Tanzania are arguably the best-known pastoralist population in the world, and the current study represents an opportunity to update and review the body of evidence linking pastoralism with polygyny. Linkages between socio-economic divergence and nuptiality are identified, with specific reference to uptake of formal education