Nonrecyclable waste glass constitutes a problem for solid waste disposal in many municipalities. Most of the nonrecyclable glass is landfilled but that does not provide an environment- friendly solution since glass is not biodegradable material. With the increasing use of fluorescent lightning systems for energy efficiency more nonrecyclable waste glass is accumulated from the fluorescent lamp recycling business. The application of fluorescent lamp waste glass as an extra finely ground mineral additive in cement is promising direction for waste glass recycling. Present study examines the effect of fluorescent waste glass on the microstructure and strength of cement paste specimens containing different amounts of extra finely ground fluorescent lamp waste glass. Scanning electron microscopy (SEM) investigations were used to observe the changes in cement hydrates and interface between the cement matrix and waste glass particles. Flexural and compressive strengths of cement paste specimens were determined.