We recall that w ∈ C + p if there exist ε > 0 and C > 0 such that for any a < b < c with c − b < b − a and any measurable set E ⊂ (a, b), the following holdsThis condition was introduced by Riveros and de la Torre [33] as a one-sided counterpart of the C p condition studied first by Muckenhoupt and Sawyer [30,34]. In this paper we show that givenand conversely if such an inequality holds, then w ∈ C + p . This result is the one-sided counterpart of Yabuta's main result in [37]. Combining this estimate with known pointwise estimates for M ♯,+ in the literature we recover and extend the result for maximal one-sided singular integrals due to Riveros and de la Torre [33] obtaining counterparts a number of operators.