Accumulating research in the past decade has shown that peripheral nerves in the tumor microenvironment have an immense potential to modulate tumor growth and metastasis. Increased nerve infiltration in tumors is associated with poor prognosis, and in turn, experimental manipulation of nerves in the tumor microenvironment showed beneficial outcomes. Increasing evidence showed that the adrenergic nerve-tumor axis promotes tumor growth. However, the cholinergic-tumor axis has dual actions on tumor growth, depending on the specific receptor involvement and cancer type. Similarly, the sensory nerve-tumor axis also has dual effects on tumor growth. This chapter covers adrenergic and cholinergic actions on tumors and their implications in tumor growth and metastasis. Specific receptor involvements and cancer-specific effects are discussed in detail. Wherever required, the underlying molecular mechanisms are also discussed in detail.