G-wires are supramolecular DNA structures based on the G-quadruplex (G4) structural motif obtained by the self-assembly of interlocked slipped G-rich oligonucleotide (ON) strands, or by end-to-end stacking of G4 units. Despite the increasing interest towards G-wires due to their potential applications in DNA nanotechnologies, the self-assembly process to obtain G-wires having a predefined length and stability is still neither completely understood nor controlled. In our previous studies, we demonstrated that the d(5′CG2-3′-3′-G2C5′) ON, characterized by the presence of a 3′-3′-inversion of polarity site self-assembles into a G-wire structure when annealed in the presence of K+ ions. Herein, by using CD, PAGE, HPLC size exclusion chromatography, and NMR investigations we studied the propensity of shorter analogues having sequences 5′CGn-3′-3′-GmC5′ (with n = 1 and 1 ≤ m ≤ 3) to form the corresponding G-quadruplexes and stacked G-wires. The results revealed that the formation of G-wires starting from d(5′CGn-3′-3′-GmC5′) ONs is possible only for the sequences having n and m > 1 in which both guanosines flanking the 5′-ending cytosines are not involved into the 3′-3′ phosphodiester bond.