Summary: This paper suggests a class of estimators for population mean of a study variable using known population proportion of an auxiliary character (attribute) which is highly correlated with the study variable. The suggested class of estimators is more general and includes the usual unbiased estimator (sample mean) and the estimators reported by R. Singh et al. [“Ratio-product type exponential estimator for estimating finite population mean using information on auxiliary attribute”, in: Auxiliary information and a priori values in construction of improved estimators. Ann Arbor, MI: Renaissance High Press. 18–32 (2007)]. Expressions of bias and mean square error (MSE) for the proposed class of estimators have been obtained under large sample approximation. Asymptotic optimum estimator (AOE) has been identified along with its mean square error formula. Regions of preferences have been investigated under which the proposed class of estimators is more efficient than the usual unbiased, V. D. Naik and P. C. Gupta [“A note on estimation of mean with known population proportion of an auxiliary character”, J. Indian Soc. Agric. Stat. 48, No. 2, 151–158 (1996)] and Singh et al. [loc. cit.] estimators. Two phase sampling version (i.e. population proportion is unknown) of the proposed class of estimators has been given along with its properties under large sample approximation. The theoretical results have been illustrated empirically by using some population data sets in both phases.