During recent years, some wildcat wells located in remotes areas of the Peruvian Amazonian rainforest tested commercial volumes of oil and gas. Beyond this preliminary success, reservoir uncertainties due to seismic interpretations, and limited cores and log data impose complexity in reservoir characterization; major sources of uncertainties can be broadly group into three main categories: structural, rock & fluid properties and reservoir performance. Applications of numerical simulation have been extended to conceptualize reservoir characterization in early development phases; coupled with statistical experimental design, montecarlo simulation and scenario analysis, numerical simulation become the most powerful tool to fulfill a complete sensitivity analysis with significantly fewer simulation runs towards sizing downhole and surface facilities, as well as, optimizing field development. The proposed holistic approach was applied to a new lean gas condensate field in the Peruvian rainforest so as to sensitize production plateau, evaluate rock & fluid properties, field size and recovery factors, predict liquid yield performance, analyze water influx and optimize field development. Pareto plots and response model surfaces showed that porosity, permeability, position of gas water contacts and faults transmissibility are the main factors affecting field size, as well as, gas and liquid recovery. In addition, cumulative plots showed distribution of gas & condensate recoverable resources. Finally, a matrix of scenarios showed that blowdown strategy is the best development alternative for this lean gas condensate field. Copyright 2012, Society of Petroleum Engineers.