Climate adaptation efforts are recurrent in the science and policy spheres, especially in the context of the adaptation of community-driven, small-scale farming systems. One such is subsistence farming, which constitutes the backbone of most rural sub-Saharan African (SSA) economies, including Cameroon. Significant research and policy efforts have been directed towards overcoming barriers to climate adaptation. Such efforts have tackled a range of socio-economic and exogenous institutional constraints. However, knowledge gaps exist in the climate adaptation literature, particularly with regards to the extent to which endogenous cultural institutions (customary rules) in SSA shape gender (in)equality in access to productive resources like land. Based on a representative survey of 87 female-headed households in rural Cameroon, we contribute to bridge this gap by determining endogenous cultural institutional constraints to rural women's climate adaptation, specifically with regards to their access to land for subsistence farming. Results were obtained with logistic regression analysis and a chi-square test of independence, showing that: (i) an inverse relationship exists between discriminatory cultural practices and women farmers' capacity to adapt to climate change, and that (ii) tenure insecurity and inequality amplifies farmer's vulnerability to long- and short-term climatic change. While this paper contributes to existing theoretical frameworks on climate adaptation from an institutional perspective, it equally makes a succinct request for further studies to be undertaken to ground this theoretical assertion.