One-dimensional (1D) organic and organometallic nanomaterials are of considerable interests for both fundamental research and potential applications. They are likely to play critical roles in improving the efficiency of various electronic, photonic, biosensing devices, etc. In this context, the authors present a comprehensive review of current research on 1D organic and organometallic nanostructures. The synthetic strategies for achieving the 1D growth are elucidated by four categories: (1) template-based synthesis, (2) vapor-solid method, (3) solution-based self-assembly, and (4) dictation by the anisotropic nature. The unique thermal, optical, electronic, field emission properties and biocidal activity of 1D organic and organometallic nanostructures are consequently highlighted. Some promising applications in (integrated) molecular electronic, optoelectronic and photonic devices are also discussed.