The interaction effects between temperature, catalyst properties, fluidization conditions, and deposition time during carbon nanotube (CNT) synthesis by chemical vapor deposition in a fluidized bed were investigated. While numerous investigations have attempted to correlate process parameters with CNT characteristics, selectivity and yield, the interaction between process parameters is often ignored. Parametric interactions in this process have been investigated using a factorial design methodology. Besides the main effects of synthesis temperature, deposition time, and catalyst type, the interaction parameters temperature-time and temperature-catalyst were found to significantly influence the resultant carbon and CNT yields. These results lay the foundation for a detailed parametric analysis toward the optimization of CNT synthesis in fluidized beds, which takes into account these interaction effects.